Double debit order deduction and very bad customer service

The worse service ever. I phoned mid September to change my debit order date from 16th to 26th of October. In October the debit order went through on the 16th AND on the 26th. When I phoned the guy said that it is because I missed a payment in May. I went to check my bank statement and phoned them again to tell them that it did went through in May and I wanted to email them the proof. Then the lady said on MTN’s system it also did go through so the first consultant ****. Then the lady escalated the matter (double deduction). When I phoned again to do a follow up I was told that the matter was escalated to the wrong department. They have to escalate it again. VERY VERY bad service