String them along. Don't lose this opportunity to make them work for their "money"
I managed 24 e-mails, a cheque out of them and even a mobile tel. number and address in London. It went on for weeks and weeks and they got more and more frustrated. Eventually, the police got involved (as I was working for them at the time).
The fun bit is winding them up over the following weeks, with them thinking they have a bite.
Go for it, play them at their own game and have some fun!