Unfair February Billing After Confirmed Cancellation at MTN Secunda

I am extremely frustrated with the ongoing billing for a contract that was officially terminated. I served a 30-day notice on 2 December 2025, and the contract concluded on 2 January 2026, at which point my SIM card successfully switched to prepaid. Despite this: I am being charged for the full month of February 2026. I have already paid my final bill on 30 January 2026, as confirmed by an MTN consultant (I have the receipt). I personally visited the MTN Store in Secunda Mall, where staff verified and confirmed that the contract is cancelled. Why am I being billed for a service that no longer exists? I have followed every protocol, verified the status in-store, and paid my final balance. I expect an immediate reversal of these February charges and a formal confirmation that my account is closed with a zero balance.