I have a samsung e420 that I bought from the uk. the seller told me that he uses payg orange sim card and it doesn't need the password, but when i use it, it would always ask for a password if I tried to access my contact list or anything. I can't reformat this either, because again it asks for the password. the seller keeps telling me there's no password. is there any way I can reformat the phone ( if any, please let me know how ) or am I pretty much doomed ? thank you.

For unlocked phones, the password is usually 0000 unless it's changed by someone else.