I'm afraid I can't help you getting a refund from that company, but if your computer still is infected, I can show you where to go to get some real help.
Try this site: http://forums.whatthetech.com/forums.html (What The Tech)
They'll tell you how to fix it, step by step and tell which is the best software to use, and I can guarantee most of the software they'll list for you will be free (Open Source). And it works. Better than most of the software you pay for. Not only that, their assistance in walking you through a PROPER fix is...delightfully...also free.
Start with the "site orientation" forum and read that - it will tell you how to get started.