No renewed contract but deducting money from bank

My contract with Mtn ended August 2015. A consultant called me in September to renew my contract. I agreed, but when they never delivered the phone on the day the promised, I called in and cancelled the contract. The told me they will cancel it in September already, but deducting money since then from my bank. Can't understand why cause I never signed anything that I received the phone. They deducting R245.00 every month and that is even more than the initial contract amount we agreed upon. My patience is up and I just want Mtn to refund me for the money they stole from my bank account for the past 4 months(september to december). And I spoke to a female consultant again on the 16th of december that promised that the contract is cancelled and I will get my money back. Still was not refunded and I doubt the contract is cancelled as yet. I just promise that if another debit from mtn is going off in January they will have to pay me much more, due to the fact that I am finishing my job this month and no salary will be paid in my account. Hope to hear from them with positive news cause I am more that FED UP now...