Southwestern Advantage Have tried for a month to get my money back and I get the run around Nashville, Tennessee

I ordered books from Southwestern Advantage on May 26th, and cancelled on May 28th, I have been trying to get my refund back and I just keep getting the run around, I have called in 8 times and each time they say I need this or that, or that they have received my fax of the yellow copy but just have not had the time to read it, or I call in and they say they haven't received it and for me to send another copy to them, I have talked to 6 different people and no one seems to know anything....Then yesterday the salesman comes to my door and tells me he has my books, I said I cancelled and he said when and I told him and he says no one told me, I said you know what your company sucks, I said I have been trying to get my money for almost a month and can't get it, and he said well it takes a long time to get it back, I said well it did not take you long to cash the check and you cashed it before it was to be cashed, and made me over drawn, so he said he would call the company and see what is going on..I said tell them I want my money by Friday the 29th and he said that won't happen and I said well ok then they leave me no choice, he said it takes at least 4 to 6 weeks to get a check, I said well its already been 4 and no one seems to know anything....So I called the company and they wanted a list of phone calls I had made to them as they could not find my call saying I cancelled...No one told me to send in the yellow copy until the last, so faxed that and now they say they did not receive it, so am going to my bank tomorrow and see if it went through and get a copy of their report....Then I called today and she wanted me to send copies again of everything, I said NO I have sent you everything you wanted me to, and now I want my money...So that is why I am here, I am tired of them giving me the run around and not having my money and the over draft they caused me to have.....