Did you attempt to deposit using the same card as your friend?
My Fiancee and I both held accounts at party when I first started out. She played Bingo or some other crap side games, I played the freerolls
and $1 SnG's. When the first deposit ran out, she re-loaded using her card on my account - both were frozen and it took a lot of e.mails to sort out.
It was obvious we weren't multi accounting as only one of the accounts was used for poker - good job else I don't think we'd have ever straightened it out.
Sounds fishy, but if its legit then good luck sorting it. FT wouldn't close your account unless they suspected they were being defrauded.