Change of bank details caused debit orders to not being deducted

Highly but highly unsatisfied with the service Im receiving. Since last year October Im trying to change my debit order details. After numerous calls to the call centre (because you are unable to resolve this on their whatsapp channel or self-service), Im still in the same situation. And when I emailed *** I was informed that it takes up to 3 months for bank changes to be activated???? Now Im 5 months down the line, and still no debit order was deducted for the end of February. Im billed for late payments, however I have to EFT my payment every month to avoid being suspended. I had to send bank statements of both my bank accounts to show that there was actually enough money in both accounts for the debit orders to go off. BUT, it was not deducted from their side. Really can they just get some competent people to work there!!!!!! Does anyone actually know what their job is there????