Secondhand iPhone problem

[NapoleonsNose]

My son bought an iPhone from a seller on eBay, well I did via my account and he transferred the money to me to pay for it. It was listed as locked to O2 which he wanted. Anyway, phone arrives and it will not work with an O2 sim. Tried with an old EE one we had lying around and it appears, in fact, to be locked to EE.

I know that we can open an item not described case, send it back and get a refund but now he has it (saved pocket money and summer job money to buy it) he doesn't want to send it back and have to wait to get another one. I want to ask for a partial refund of £20 to pay EE £8.99 to unlock the phone and a little bit extra to cover the inconvenience of having to do this. Is this unreasonable and am I going to have to send it back anyway? Its a reputable seller, with feedback close to a million and I have bought a phone from them before.

The £8.99 to get it unlocked, fine. The rest for the "inconvenience", not fine (IMO). You haven't lost anything.
I'm an eBay business seller and I think a partial refund to cover the unlocking cost and a refund is adequate.

However, the seller is under no obligation to offer a partial refund. You can ask, but They may just to tell you to return for a full refund.

PS are you sure you can even get EE to unlock the phone? I thought with iPhones it needs to be the original owner, or you need to have used an EE sim in it for a certain period of time?

No, I've done it twice before, both with secondhand iPhones. DS is already on EE so it's not a problem. Tbh, if they say to return it, I will probably just pay the unlocking cost anyway to save on having the hassle of returning it. It was just a bit annoying that he was so excited about having saved the money and being able to use it straight away and then wasn't. I'll see what they come back with. Nothing ventured, nothing gained!