Incorrect debiting

I renewed my contract with Telkom December 2025, the told me I will be now paying R998 moving forward. Come January they debit R817 which was the amount of my previous contract. I go to the store they advise the R817 will be credited back into my account and the correct amount will be debited. That doesn’t happen instead the try to debit R600 I don’t know for what, then they recently tried to debit R1800 and they say it’s including this months payment which is only due on the 26. Telkom now closed my lines because of their error!! The incorrectly advised and incorrectly debited. Now my old Telkom line is closed yet I paid for it. I’m so annoyed!!