funds not collected

MFC debit order goes off from my bank account on the 1st of every month and now they says they did not get my installment because I had an insufficient funds into my account which I do not agree as I have never receive a message of a returned debit order from my bank and the funds are still there. Since then I made queries about this but nothing happen, they loaded a debit order for several days and still nothing happen. On Friday 04/12/2015 was my last quiry and that was when I asked their account number so that I can pay via EFT and the consultant who was helping me refused, he said the debit order will go off on Saturday and still nothing happened. Can someone assist me please, this thing is bothering me as I can not afford to pay two installment in a month.