Auto Marketing Systems AMS cold call cell phone contact, would not refund all of my money 10-minutes after they took my information Roanoke, Virginia

Auto Marketing Systems somehow obtained my cell phone number and called me regarding the sale of my car. Like a fool I signed up for their service paying $149 then googled their company and found numerous complaints around the Internet about their deceptive offers, harassment of potential customers, failure to refund $ on their money back guarantee, etc. I called AMS immediately, within 10 minutes of signing up for the service, and they refused to refund all of my money. They refunded $120 and said they had to keep $29 for a processing fee. I'm wondering if there is a possibility of a class action lawsuit against this company. Also, I want to warn everyone about their tactics. I'll never break my rule of doing business via telemarketing/cold calls.