To be angry with holiday camp?!?!

I'm with you on this. My son's camp do day trips every Friday and so he won't go in on those days. I don't want them taking him offsite but he is younger than your DD.

Really? No permission slip? No note with a run down of her day and she will need to bring/packed lunch/sun cream etc. I find that very hard to believe.
Your daughter wasn't talking about London tomorrow etc.

It all depends on the communication. If something was sent out, eg 24th July will be our trip to London, with an itinerary, I would assume you had to communicate with them separately if you didn't plan to attend. If they just mentioned something verbally it would not be as clear. You must have had to sign something though. Was there no paperwork for this particular trip, or when you sign them up for the camp do you agree to all trips?

There wouldn't have been just 1 staff member left with the children.

Didn't she mention she was off in a trip tomorrow?

I think they're fine in enclosed spaces where the kids can't escape, the camp staff just kind of work it out as they go along. I'd be wary of roads/water though, and I've never let my DC go to any where swimming/pool games have been offered as activities.

I think your assumption is reasonable - full day trip for the full day kids unless clearly communicated otherwise. There could easily have been one staff member staying back with the e.g. 4 half day kids.

This, we're here all jealous you've scored a free afternoon of camp

I’ve haven’t sent my children to these style of camps as I remember being a teenager and being ‘friends’ with those that went being ‘camp leaders’ for the summer. They were nothing short of children themselves, still making daft mistakes and figuring out life. I understand your anxiety.

That said, I wouldn’t leave them in the care of a camp run by kids full stop.

I wouldn't worry for today, but yes this is something to think about going forward. It depends how much you trust the staff and how competent they seem, but also how much you can depend on your child's streetwise/good judgement. I would be comfortable with my 8yo doing most things while being supervised by a responsible teenager, but I still keep an eye on some of his friends next to the road as there are a couple who can be a bit unpredictable.

Unless you've missed a lot of info from your post it seems incredibly gung ho of the staff.
No signed agreement/disclaimer?
No extra cost for the trip?
No asking you to pay for the afternoon session when you hadn't booked it?
First info was a text about the trip today?

My kids used to go on some trips with holiday club and the dates were set way in advance, forms had to be completed, there was an additional charge payable in advance. If they didn't have enough numbers or short on payment it didn't happen.

How the heck did they take an 8 yr old on a trip to London without specific written permission to be off site with the child. Every time I have signed my DC up for something that involved being off site there were loads of forms to sign, instructions home about taking more snacks/water bottles/suncream/hats etc.

I think you were entirely reasonable to assume that since you had signed your DC up for a session that ends at 1pm (and paid), that she would be there for you to collect at 1pm.

Its very worrying that their paperwork is so lax that they either didnt communicate it properly with you (along with a new time to collect her), or didnt realize that she wasnt signed up for it and took her anyway.

If it’s a camp that does trips and you signed her up for a trip day I’m not sure what you expected? If you didn’t want her to go on trips then why would you sign her up for one?

My kids’ camp has trip days but there’s no one left behind - anyone there is on the trip with the teenagers and managers who aren’t teens.

This makes no sense. Why didn't you ask? Why have they not asked you if she's in for half day? Didn't you give her a lunch? Where are they actually going in London and how are they getting there?

I agree with you, I am surprised the club are doing a trip like that.
But you also did an awful lot of assuming. in future just ask

But surely you knew she was attending. They will have taken lunch, mentioned the itinerary, transport or something and at 8 she would have told you she was going to London tomorrow?

Surely they would have needed permissions and payment to do a trip like this? Travel costs for a start and any attractions they do in London. I would be very confused and not happy about it either op.

There’s obviously been a misunderstanding/some confusion.

Did you send her a the a packed lunch?

I can’t really say that you should be angry with the camp or not because it’s impossible to say whether it’s their mistake or yours.

However your dd will be fine and I bet she’s had a lovely time.

But if the club was going on an all day trip where did you think she would be. This trip will have been planned and risk assessed. It is vanishingly unlikely that anything will happen to her. Especially if she is sensible and can be relied on to follow instructions.

Why else would they text you about the trip though? If the trip is part of the schedule all the children at the holiday camp would go.as they wouldn't have enough staff otherwise

And I agree with you that I wouldn't be entirely comfortable with teenagers taking children of under 8 on a trip like this. So it depends how old she is.

The little ones can still be a bit unpredictable around busy roads. I've seen lots of school trips in central London (often there for work) and the teachers have to be so, so "on it" with the kids. Whereas at 8 and older, you'd expect a reasonable amount of road sense and basic self preservation instincts.

But she's there now, they've run these trips before and chances are nothing will go wrong.