Great American Readers won't let me cancel my subscription and says i will owe over $700!! Internet

I wanted to cancel my magazine subscription and was told i could not.This company called me one day very early. They told me that i could get a magazine subscription for only 39.90 and then i would be mailed a gift card for agreeing. I thought, well thats not a bad deal and i get a gift card.

 I started receiving the magazines they said i would, and was also receiving ones i did not agree to. I called every magazines cancellation website and many of them had no problem canceling them, others directed me to the company that is providing them, Great American Readers. I tried calling them several times with no luck. 

I finally got ahold of them. I spoke to one lady and told her i would like to cancel my subscription. She told me this was not possible because i have several more payments that need to be made. I was taken aback by this. Several more payments? It was supposed to be only one.

She told me the agreement is 39.90 for 20 months. She told me she would be able to work out the payments with me. I said i did not want this! I do not want to continue getting magazines and paying for them. She told me she would be able to look up my recorded tape and review it with me next week. I agreed to that. 

I also said to her that i feel i should have gotten a copy of a contract or something. I asked her why i did not get a copy of a contract. She told me it should have been mailed out. She said it was sent out, and it should have come to me. I told her i never received it. 

I than asked her about the gift card i was supposed to receive for agreeing to this. She told me the release for that would have been mailed out when the agreement was made. I never received this either.

She said it was supposed to come with the other thing that was supposed to be mailed to me and that it may have gotten lost in the mail. She asked me if i would like it sent out again. I told her all i want is to cancel my order, i do not want to pay 800 dollars in magazines.

She told me she would get back to me early next week with the tape. After i got off the phone with her i started researching them, something i should have done before i agreed to anything, but like i said it was early in the morning and i clearly was not in my right state of mind half asleep.

I found that many people have filed complaints against them and many complaints have been closed. All i want to do is cancel the subscription. I do not want to receive any more magazines. I do not want to pay for any more magazines!