your Credit/Debit Card issuer & given them the facts too? I would.
Might also be worth letting Trading Standards have a copy of all msgs to date too.
I was stung 2 years ago by a firm offering ex-rental videos, who took the money but didn't deliver, or give a refund, despite many emails. Needless to say, phone/fax calls went unanswered too. It took 6 months to get my cash back (over £100), but I got there.