To think she lied and actually went?

Well, OP? Is your friend back at work? What did she say?

If friend is lying, it’s weird - but OP hasn’t actually lost anything. If she was happy to sell her ticket at a loss so that her friend could take someone else, why does it matter if it was resold to a stranger at a loss? OP might think she could have got more than £100 for it, but unless someone has actually offered her £125 for it, she doesn’t know. All she’s basing it off is prices on reseller sites - and as another poster pointed out, those tickets by definition had not sold at that price. And I and others have commented on the difference in value of single tickets.

In any case, OP’s argument is entirely based on assumptions at the moment. She assumes her friend went because she’s off sick. What if she genuinely is sick and hadn’t even remembered the date of the concert? Or what if OP’s right and friend did go - how does she know that she might not say tomorrow “By the way, I was able to go after all as Claire bought your ticket” or similar? And if OP - who doesn’t seem to trust this friend very much - had agreed to sell her ticket to friend’s friend for £75 (for example), how does she know friend didn’t actually get £100 for it, or resell it instead of inviting someone else? If she doesn’t believe her now, surely friend would be equally capable of lying in that scenario too?

And friend said she did sell them, I'm confused about why OP thinks her friend is lying to her. She could have sold them privately,

She said no and said she could only get max. 100 for them. I looked on resell sights and said oh they are going for more though.

Maybe for pairs of tickets. Single tickets aren’t in the same demand. Sometimes you can get a real bargain if you’re happy to go somewhere alone. Equally, sometimes if a venue has a pair of seats available, they won’t let you buy just one, because it makes the other seat less desirable.

I find it best to save up some money in a bank account so that when large unexpected costs come in I don't have to mess people around.

Worth thinking about.

Regardless of who's at fault ... What does it matter if she indeed went to the concert? Literally what is the problem?

You must of not read the OP correctly where she said she was happy to take less money so that her friend could sell the ticket to someone she knew.

You must be a rubbish friend if you think it’s OK to lie to someone and pretend to be sick to go to the event you apparently sold the tickets too

Going completely against the grain here.

Although OP hasn’t clarified she has stated she had an accident and unexpected bill so I’m assuming something along the lines of car accident.

If you are a true friend you don’t take advantage of your friend like this, yes it’s understandable to be sad that a month before the concert your friend can no longer go. I would never lie to a friend and pretend to sell them for a low price, no proof of selling the ticket that OP has paid for, then take a day off sick and go anyway.

In my opinion life sucks and sometimes accidents or bills happen, how is OP a CF? She told her friend straight away. Her friend doesn’t have the right to lie to OP.

OP she’s a crap friend and you deserve better x

You let her down. She obviously wanted to still go. It was better for her to not sell your ticket to an unknown person for an inflated price. As she probably wanted to take someone she knew! You're being very selfish.

Ask her for your share of the sold tickets.

She can do what she wants.

She maybe had someone else who wanted to go with her so gave them your ticket? She could’ve given you some money but I do think as you let her down it’s not really your circus from there onwards x

I think at the moment you let her down it’s none of your business what happens next?! I don’t see why you care either tbh.

Read the OP she asked her friend if she still wanted to go she'd sell her ticket for less the friend insisted she'd rather sell both. Then sold them under what they were worth & went anyway... ?

Should have just been honest & she wouldn't have to miss a days pay avoiding an awkward situation

Yes, sure but personally I couldn't be dishonest as a friend and make a profit out of another friend if I had managed to sell on the ticket.

But friend presumably only bought the ticket in the first place to go with OP, she might not have wanted to go alone, so it's not just about the money, even if she got a full refund she'd still be disadvantaged.

If OP wanted to sell her own ticket she should have said to friend "I think I can sell my ticket for more than £100, its my ticket so its up to me what I do with it."
Of course she probably wouldn't have got much more because a) the market for single tickets is lower because again a lot of people prefer to go with others and b) the whole point of the price on resale sites is those are the tickets that haven't been re-sold yet. you can't look on viagogo and say "oh they've got tickets for £200 so that's how much I could sell mine for" because if people were willing to pay £200 for those tickets they would have, meaning they would no longer be available for you to see how much they were on for!

I think if you drop out of something then unless you've got a guaranteed refund policy with the organiser you accept you've lost the money.

Don’t really think you have a good reason to not trust her
you have no proof of anything
have you asked her ?

Just because there are high prices on a resell site doesn’t mean anyone will buy at that price. You should have also checked availability on Twickets in the days before the concert. If it was a big stadium gig (eg Robbie Williams) then there would be loads on Twickets including below face value.

In that case I’d message and say ‘you know you sold my ticket - would you be able to send the money? I’m a bit out of pocket after that stupid accident left me with a bill for XXX.’ @Summersparkles123

I’d have been seriously pissed off with you for pulling out. For such a lame reason.

I hope she had a good time if she went.

Going against the grain, it's the OP's ticket which she paid for and gave a month's notice that she would not be able to attend.

If the friend has been able to sell the ticket on to someone else at face value then she needs to reimburse OP. Either way, the friend needs to be clear what happened to the ticket.

If it was a last minute flake out or if the OP never paid that would be different.

For whatever reason, you let her down and piked out.
Your friend deserved to attend with someone she knew.
As long as she reimburses you what she sold the ticket for, you should be fine.

She also hasn't paid me the money for my ticket yet

So you told her a month ago you couldn't go and she agreed to buy your ticket from you? @Summersparkles123

Technically the ticket belongs to OP. But you should try and minimise the inconvenience to friend by allowing them to take someone else, if you get some money back great but I wouldn't be looking for it.