Account Details not updated after I phoned to update it

I am very upset that my account had to be transferred to the collection department ruining my credit score as i will be recorded as a slow payer because of an unprofessional Telkom employee whom i asked to update my banking details on the 14th of September 2019 and never did.

This was not done and hence resulting in Telkom not debiting the monthly fee in the month of October forcing me to make a manual payment. I have been calling telkom since the 1st of November to beg them to debit their monthly fee but they still have not.