MTN agents added new contracts on my profile without my concern

I'm Tertia and I am very upset with the service from MTN. I called in early November to cancel my one contract that expired in October. I spoke to an agent she said she's canceling for me. Today MTN debits new high amount installment and I call in only to find out the previous agent I spoke to has decided to add new contracts on my profile without my concern just to make a Sale. This is ***** and I want this attended to because when we go to MTN branches we are told calling is the only way what's the point of having branches if we can't be assisted there. I will not pa