bad contract deal

I'm regretting my 2 1/2 hours on the phone yesterday with att because I now am going to pay $70 more a month for the same service that I had, since my "contract" expired. I'm on the hook for 2 years and they have to come in and change out my system and re-issue everything to give me this incredible "deal"!!!!! I think I must have just been worn down by the long phone process. They're closed now until monday, how long do I have to cancel it all without penalty? I want to take it all back and start over with a chance to look at other options. Please help.