Forgotten passcode, apple id *and* password

Hi,

Just wondering if anyone can help out. A friends daughter recently left her iPhone in a foreign country with a friend accidentally and had it returned. However, with using a different phone in the meantime she had forgotten the passcode for the iPhone.

I suggested that the only thing that I could do would be to factory reset it, so that she could sign in with her Apple ID to re-activate it.

I've done this and, now it turns out that she can't actually remember the e-mail address that she had originally signed up with. We have the 'clue' with the first letter of the email address and the domain. However, she can't remember what the actual e-mail address was so recovery of the ID is going to be difficult at best.

Don't ask - I'm stumped myself as to how they've managed to achieve this!

Anyhow, the phone was purchased by her, and we have the proof of purchase for the phone. Is there something that could be done, even if it has to go back to the Apple store? Obviously, we're trying to avoid a hefty replacement cost if we can as there's no fault with the phone (just obviously a fault with the user!!).

Any help would be appreciated.

TIA