5 Day overdue amount off set against salary

We have been having some financial difficulties due to illness. our home loan account has been in arrears for a while with a 30-60 day balance , but we always made sure that we made payment of at least a full installment every month which lead to us having a 1 month overdue amount that carried through each month. i got paid on the 25th and on the 26.02.15 i was at the atm and saw that an amount of R2962 was taken out of my account, this lead to all debit orders returning unpaid each time costing me +/- R100. that offset brought our account up to date and on the 28.02.15 the normal installment was due , a few days late with the installment, i go to the atm today and see that they took out another R2962 which leaves me with R850 for the month for a family of 5. I called the call centre and was told i agreed to them <br> doing this when i took out the home loan in 2005, she then transferred me to the complaints department, the lady didnt ask details and when i am trying to explain all i get is attitude. This is really the last straw