Account Debit

I am ****ed, so to avoid missing any debit orders I pay my account in advance but then Telkom still tries to debit my account on the last day of the month, which is fine cause they can always refund me right? Wrong they keep debuting and returning funds to my account only to leave me with a charge of R 150 per transaction failed. So basically I’m punished for paying my account upfront, I regret the day I bought a device through telkom honestly