Telkom contract nightmare

I requested an early termination for my contract because of constant suspending my account for no apparent reason, they would claim that I owe them whereas the account is being debited monthly and I never miss a payment I had to always call in for them to fix the error. I have two phones with them one phone contract expired in December 2022 and I requested for an early termination for the other one too. an invoice for January 2023 came including the total amount of funds for the remaining months of the 2nd phone. The invoice says they would be debiting the amount of R7 547.00 on the 20th of January. to my surprise they suspended the 083 number on the 16th of January and today which is the 18th of January they have suspended the 073 number. saying I have reached the credit limit. why dont they debit the amount on the 20th then if they can't get the money then suspend the account ? the account number for the contract is ***.The experience with Telkom has been painful and frustrating.