Telkom they are not fair, being charged for something that I did not sign. pathetic

I am not happy with Telkom, I have been a loyal customer for such a long time, currently I am frustrated with their services I signed a new contract on the 25th September 2024 month-to-month unlimited data for R449. I had a contract for R105 / 20GB simcard that I was using, then at Telkom Centurion Mall they cancel this contract when I was upgrading to R449. To my surprise I received a bill stating that I am owning R1695.05 I signed 2 contracts for unlimited data of which is not true. I’ve being going ups/downs to the store also calling the customer service still there’s no solution no joy. And they will deduct this lot of money from my account that I do not have I will leave with nothing from my account. They are telling me about subscription that I subscribed that I do not even know off. The old contract was for R105 monthly not R600 something. I asked for arrangement still they are not helping me. Please help me.