mtn insurance ****med me

when I renewed my contract with MTN in 2019 December, I made it clear that I did not want any insurance to the phone. they went ahead and debited my account against the insurance which I did not take. upon inquiry I was told its a mistake which they will rectify. All they did was to stop the debit but did not refund the money they took without my consent for 4 months. to date they still play hide and seek after exchange of 52 emails. they keep requiring my bank statement which I have provided to them thrice already. my query is being handled by different people all of them learn about my query and require same information over and over again. some days they said they have referred my query to their finance department while on other days they said they will not pay me as I cancelled the contract. ITS IMPORTANT TO NOTE THAT I DID NOT ENTER INTO ANY INSURANCE CONTRACT WITH YOU IN THE FIRST PLACE, I DO NOT KNOW WHICH CONTRACT ARE YOU REFERRING TO BY 'CONTRACT CANCELLATION' PLEASE PAY BACK MY MONEY!!!!