MTN end of contract billing problems always

Email Address *** Date Transaction Reference Amount Due Date Open Amount 01-12-2025 Invoice I*** 485.00 01-01-2026 485.00 01-11-2025 Past Invoice I*** 324.09 01-12-2025 324.09 Your total amount due by 01-01-2026 R 809.09 Billing Account BA*** Number *** Due Date 01-01-2026

My 12 months contract ended 30 November and my last debit order was on the 1st December 2025. I have cancelled the contract and returned the router ref: ***. I keep getting sms about how I'm now being moved to month to month contract, How am I still billed for this service. I went to Boulders and Mall of Africa branches to query about this and now I am getting invoices. Both MTN branches told me that the contract I had I couldn't do an upgrade because it was a 12months contract. Last year MTN employee committed ***** and did an upgrade BA*** *** December invoice I***. I had to fight to get that resolve. Its a thing with MTN now. Please fix this ASAP because I'm not paying for this