Settled account yet still deducting!!

I settled my account on 31 January 2018. I followed the instructions to the letter to ensure that they do not do another deduction in February. Bear in mind that my payment date is the 25th, so in essence I made a double payment in close succession of each other. Low and behold, a deduction is done on the 25th of February!! When I called it took me 30min to get through and then another 15min of being transfered from department to department, because, "they can't find my account". How is this possible when they were able to deduct???? I again followed their instructions and sent an email to their customer care, 48hrs became a week. I was then refered to the refunds department, and once again I am waiting. It's almost the 25th again. If this is not sorted within the next 24hrs, I will have no other alternative but to go to the Obmudsman.