Over billing for 2 months already

REQ*** Last month on the 2nd February I called for the first time and logged my complaint wrt being over billed. Only to be over billed again with my 01/03/2024 billing. When I called on the 2nd of March a month after my previous call I was advised that they can see that as of my next bill I will no longer be billed for the free handset however the refund request was never done. She then escalated (according to her) to her manager and the relevant billing department to process the 2 months refunds onto my account before the refund can be made to my bank account. She asks me to follow up because apparently they cannot depend and rely on technology. I follow up 24 hours later, no one has attended to the escalation another almost 36 hours passes. No one has attended to the escalation. What was the point of escalating. What is the slap for escalations a week. MTN are in breach of their contract with me. They debited my account for more money than what I ageed to pay in my contract.

Had the roles been reversed annd I owed MTN money they would have disconnected their services already.

Can someone with some form of authority please attend to this urgently.

Thanks