MTN *****ing money from non account holders

In Oct 2018 n received an email to my personal Gmail account from MTN stating a payment was due on my account. The email was not addressed to me, but someone else. I contacted MTN to tell them I am not their customers and that they send it to the wrong person. I had an account with MTN, but closed it in 2016. They confirmed this was a mistake and they would fix it. 10days later I get an MTN debit order on my bank account. Again I call them to tell them I don't have an account with them, again the shop manager at MTN atterbury confirms this is a mistake. The true account holder gets in touch with me, and copies me in on her email to the store with her bank statement and proof of residence. A month later my account again gets debited. Again I call them and the account holder goes to the shop to take them her papers. Patrick the shop manager says it was an input mistake and the shop assistant who did this resigned. He assured us it was now fixed. The next month again I get debited. I lodged 3 complaints on the customer care line over 2 months, each time they tell me I need to fix it and send the store the documents. We did this 3 times, I called 3 times, the account holder called several times and went to the store twice more. Guess what I received today... My notice of the debit order on my accoynt. I am at a loss of how else to fix this, clearly the store manager Patrick is completely *********** and has no idea how to capture data in the system, and customer care does CARE a bit as long as the account is paid. I am short of walking into that shop and cutting every wire in there till the regional manager arrives to fix this mess!