Account Billing Bad Experience

After being a loyal client of telkom for more than 7 years I've been experiencing bad service with the billing dept since last year July when I took a 2nd phone on 1 contract, my debit order amount that was agreed on as per contract is not being debit correct I'm being debited more 1st started as a once of payment on a wrong debit order date service request have been loaded several times bt the Garden Route Mall branch till this past Sunday but this is just not being resolved, I am paying via EFT monthly the correct amount as per contract agreement, this issue with the billing dept has led my account to be in arrears and additional fee are being charged extra whilst I'm even paying via EFT monthly. What they do they are blaming each other instead of fixing my account billing issues. The call center agents don't even care about the client enquiry and font show any sense of urgency in trying to resolve this issue so they are so unprofessional. I so tired of Telkom I even regret being their client