MTN de***** their customers

MTN is a ***** nje, this is after they keep debiting me whereas a contract is no longer in place. I had a contract phone with them, had the phone insured and late last year the contract period ended and the contract officially cancelled. In November I called the insurance company and cancelled the contract with immediate effect and the last premium would be in December. After having cancelled the insurance MTN decided to debit me in January, I contacted the insurance company and they requested an invoice which I submitted but to date never got my refund. Now in February I got debited again for the second time since cancelling the contract and now when I followed-up it's only when they decided to ask me about a pin. All this time since my initial refund claim they never reverted back to me so meaning if I had not followed up I would probably forfeit my funds. I as told the pin is incorrect, as if they can't help me, but I really don't care about the pin right now as I want my money back, which I was debited without authorising that. So I have been ********ly debited by MTN for a contract (insurance) that no longer exist. I really wonder how much money they're making from all these ********** debits they're making. I want my money back.