Action Pro White Not return my money as promised Henderson Nevada

I purchased a teeth-whitening product which I decided not to use. I arranged to send it back to the address in Nevada, via a CSO working for the company, and was informed that I would get a refund. I put a code on the return package, i.e. RMA 11-558013. When I did not get a refund I contacted the company who did not acknowledge the RMA no I was given and said, more or less, that it did not exist and I did not receive a refund. I went to all the trouble of returning the package and paying for the postage and then did not get my money back, even though I was told I would.