MTN Insurance - Incorrect Debit

MTN recently added insurance on my bill for a phone I never requested insurance for, and they even included a pro-rata charge. I have requested a refund, and they are taking their sweet time to refund me even though I have submitted the information they needed (i.e., insurance waiver, banking details, contract summary, etc.). It was *********** of MTN to allow this to happen, and they need to improve quality checks on monthly invoices to avoid instances like mine.