Supposedly "stopped" debit order went through again

I have lodged a complaint end of March in connection with a debit order that I could not dispute or stop. On the 27th of March I did receive an email (with reference number) from FNB that they will deal with this matter, but on the 1st of April that SAME debit order went through once again. I responded to that email informing them that this particular debit order went through again and up to date no response or resolving this matter from their side