DISGUSTINGLY upset uboit the way my account is being handled at Telkom mobile

Month end August I switched banks from a global account held at Capitec to a Current FNB account. FNB switched all my debit orders including my Telkom mobile account to FNB. Month end august I gor over billed and the call centre agent explained that for a penalty for a debit which bounced, fair enough clearly FNB did not switch switch the debit in time I thought to myself. During the same month I went and ensured that Telkom has the correct new FNB banking details by isssuing them with the latest bank statement. Come month end Sept, i got overbilled yet again, which the call centre agent explained as a bounced debit from their side. Fine I let that slip occe again but wen to the branch again to ensure the correct bank details which they were fine. Month end of Oct same thing, even now as I write this complaint I just got overbilled which the call centre agent explained as a debit which bounced..I am Utterly ****en ****ed off as I fill helpless and ****ed off..because all they keep saying is "bounced debit" of which there is always funds on the debit day that I specified to be on their system. I FEEL LIKE BREAKING SOMEONE or vent out somehow because this is my hard earned moneynthey messing with and its ****ing up my budget everytime this happens.. I most definitely would not consider renewing my contract with them as I am close to finishing this mobile account. WORST EXPERIENCE..****!! ???