BillingWare Was naive in accepting the add, and now can't get rid of program!! I'm very angry!! Internet

I was on the Internet, Friday August 1, 2008 at around 2:10pm, when an add popped up. It said to try this antivirus program and have a free scan etc. So I downloaded the file and it scanned my computer! It came up with trojans, malicious files (their words) etc. I pressed the Remove button only to find myself at the website. The first page has nothing but 3 programs and 3 prices and of course a button to refer me to the credit card page. So I clicked on that button and it took me to the credit card page. At the bottom of that page was a link called Customer Support. I clicked on that and it took me to a bare bones page with the email address of support@billingware.net, the phone # is only for authorized users and no physical address.

The program either titled 'Antivirus 2009' or 'Billingware' is not found on my "Add/Remove Programs". I don't know how else to get rid of it. Ads keep on popping up about every 4-5 minutes.

I'm about ready to scream! Any suggestions on how to get rid of this program?

Thanks for any help,
Anya

Anya
Salmon Arm, British Columbia
Canada