TELKOM I WANT MY REFUND

I am so disappointed with TELKOM FIBRE BILLING with the type of service I have been receiving, sent a change of banks in June to them in July the still debited on an incorrect account they promised to waiver my missed debit fee until they were done however they didn't it still happened the next month. I've been incurring ridiculous bank charges because of them, we are in September and nothing has been finalised as the same extra R200 charge happens every single month for their mistake ,they don’t wanna refund me for the double debit they made they telling me it will be credited next month but guaranteed that won’t happen because it’s been going on for months 💔What bad customer service is this?