cctv services inc. cctv services Over charge my credit card Farmingdale, New York

I called them for installation of CCTV on my store, and ask for a price quote. The phone representative insist to send someone from their company to my store to provide that estimate. They send someone that told me that the total price for the entire job will be $2,200.00. He showed me a list with some of their customers (later on I found out that it was a lie, none of those customers on his list were his customers). He asked me to sign a contract with a lot of small letters.  I signed that and gave him my credit card. They charge my credit card for the amount of $4,500.00. I called them and asked for refund, and their response was that I signed a contract that allow them to charge me more. I dispute the charge on my credit card, as result of that, I got into a long affair with a collection agency.