Poor Service

I got a contract at Mtn but the lady that sold me the contract told me that I have a month free and can cancel in the first month.okay... So I said okay its just for a sim card with data and airtime.So my package arrived and I got to sim cards one is the airtime the other the data I don't know why 2 separate sims but okay. I didn't recieved my contract papers or anything via email I didn't sign anything and i didn't gave permission for a debit order. They debited my account and it was way more as what I was told the monthly bill would be.So I tried and tried to get answers for a month and to cancel the contract because I m not satisfied with the poor service I recieved. I'm still waiting for feedback.