bad service

On 02/02/2015 I went to nedbank to do stop payments on my debit orders as I had lost employment. They charged me for that service but to my suprise those debits tried to go through and I was charged for unpaid debit orders. Again in march one debit order went through and left me owing, by the time my Nedlife insurance tried to deduct I was already overdrawn which again I was charged for. This led to my policy of 10 years lapsing plus I paid for the unpaid debit. It is your fault that the liberty instalment went through whwen it was not supposed to how can I then be charged for it. I want a refund of all the unpaid debit order charges on my account as a result of your negligence.