DOUBLE DEBIT

I am once again so disappointed to have chosen Nedbank as my Home Loan Bank. I have been treated so unfairly on numerous occasions. This time I have been debited twice in the month of April on my home loan. When I reach out to Nedbank I am taken from pillar to post. I am currently sitting on a huge NEGATIVE balance on my account that yet no one from Nedbank cares to communicate with me about. I FEEL DISAPPOINTED, INCONVENIENCED AND MOST OF ALL STUCK as I cannot even afford to buy bread for my children at this point. Please help