litigation law group scammed on my lowering down my interest rate, but never did Internet

I received a letter from litigation law group, at first, I thought it was from my bank, however it was from litigation law group. The letter stated that I could get a fixed interest rate at 2.00 versus 6.8 that I have now. So it looked so attractive to me. Then I called up the number, and spoke to a representative named Tony, initially he asked couple questions over the phone, and said that i was approved to get a lower interest rate. Then he asked me to send $3000 check through UPS, with some documents provided. Tony said that I could get a full refund. Two days after I sent out the check, my check got cashed, and I changed my mind. I would like to cancel the service, and get my refund, however Tony wont let me. Then he said give him a week, to work on the cancellation file. I gave him a week. then he transferred me to another department, a guy named Lewis asked me to send a request of cancellation, in order to process my cancellation. Then I sent out the letter. I called up few days after, and asked for lewis, he said I needed to speak to Paul about refund , however Paul was out for vacation. but no one told me he was out for vacation, I called up each day to ask for Paul, and left messages. No replied back!!!!!!! 3 weeks later, when he came back, he called me, he said the most I could get was $500. Each representative tells different story, its a scam, beware !!!!!!!!