Terrible Service in Accounts Department

My debit order was not deducted for April. I phoned RCS and arranged for it to be debited again and to make sure that the debit order is loaded on the system. They said it was. It happened again in May. They blamed the bank. The bank said the debit order was never loaded. Had to phone RCS again to make sure everything is okay. They promised it would be sorted out. Same thing happened again in June. I spent HOURS on the phone with RCS (at my own cost) to determine the fault. I answered the SAME questions every month, over and over. I do not live near a store where it is convenient for me. I had to make my payment for June via EFT because of the debit order not going off. I made payment on June 6. It is June 23 and they still haven't picked up the payment even though I have sent the proof of payment through three times and spoken to them over three or four calls. They phoned me yesterday to say that my account is in arrears and that I will be debited the amount AGAIN in July (curious to see if they manage to load the debit order this time!). I have reference numbers available. I am being charged interest on their incapacity to deduct a debit order. Frustrated.