MTN incorrect Billing

Early January in done an online upgrade on my MTN contract, I got a call from the lady from MTN which assist with the upgrade, 3 days later I thought to myself why take a contract phone out if I can buy it cash. I called in to MTN 808 number, cancelling the contract, the lady whom assist me said she will send an email on my behalf cancelling the contract. I received my January bill and I was billed for the new contract, I called MTN again which the MTN staff transferred me up and down for the whole duration of the call. I called again in last week and again I spoke to a few please sending me up and down. I got new refers from last week calls. REF ********** 9 and Ref ********** 18.. up to today I was told that Christ would call me and in my February bill I’m charged again with the new contract value. I will not pay the bill. I will not pay anything on this bill and any legal fees.