Debit Order/EFT Payment NIGHTMARE

I changed my bank in February. I knew that my debit order would not go off on the 27th of February, so I made an EFT payment to Cell C Service Provider on the 1st of March. When I received the Statement from Cell C in March, this payment was allocated correctly. I changed my banking details in early March via the Cell C call centre, and the lady failed to inform me that the change would take a month to happen. On the 27th of March the debit order did not go off, so by the 2nd of April I phoned the call centre to enquire why the debit order did not go through. I was told that everything was fine, but that I would need to do a EFT again as the debit order cannot go off again. On the 4th of April, I paid the outstanding amount into the same account that I used on the 1st of March. This amount is now not being allocated even though I used the exact same details as previously. I have phoned the call centre, I went to Cell C Springs Mall where the lady there phoned Cell C Finance and spoke to them, I spoke to the call centre again, I sent MANY emails to Cell C collections, Cell C Manual Payments and Cell C customer Services. Everyone just tells me that the problem will get escalated. I get NO feedback whatsoever, only reference numbers and I do not even get an answer back from emails which promise a 24 hour turnaround time. I am so tired and angry with the lack of service I am getting from Cell C. I cannot for the life of me understand why this payment cannot be allocated like the payments were allocated that I made in March. AND to add insult to injury, they are now penalising me with a R70 debit fee penalty after they failed to informed me that the change of banking details will take a month to happen. I just need Cell C to PLEASE allocate my payment correctly.