SpeedSounds, Inc Sending a defective product and not fulfilling return policy Murrieta, California

I ordered a piece of car stereo equipment from SpeedSounds, Inc. I emailed them replying that I would like my refund under their 60 day money back guarantee because they sent me a dis-functional product. They said they would refund my money but never did. I had to contact them saying I was going to contact the better business bureau to even get a reply. Now I used a loadable credit card to make the purchase. These cards can not be refunded to yet they insisted that's how it would be done. I require a check to even receive my money back. They also cut the refund amount down to almost $60 without mentioning their refund policy. They are currently trying to resell the product as well as they re-posted it. The product is nonfunctional and someone else will fall into their trap. In short all I am asking for is a proper refund via check.