Selling a home?

I did a base contract with a real estate investment company to sell my home. They lied to me about price and other things. I want to cancel the contract but they will not respond to me. There is a 90-day period on the paperwork but nothing about cancellation or anything. Do I have to wait the 90 days? This is not a legitimate company. They took advantage of me and I will not allow them to sell my home and I am not selling to them. They have spent no money in advertising or anything so can I get rid of them?