Over Debited

Further to my complaint on the 26th of May, I received a call back to say they apologise & that they had rectified the problem but then received sms after sms to say that I had reneged on my payment & that I would be handed over. In June, same thing happened - two out of three debit orders were correct so reversed the incorrect one & transferred the arranged amount but still received sms after sms threatening legal action against me. Again now in July I have the same problem, now two out of the three debit orders were incorrect & the third hasn't come off at all. Once again I have had to reverse the two incorrect debit orders. I want these debit orders cancelled immediately & I will pay by EFT as I did in the past as this is causing me unnecessary stress