Unauthorized debit orders in my cheque account

I have been complaining about FNB housing Finance deducting R110 from my cheque account for a while now, but none of those complaints have been resolved. I have been given reference numbers for my queries, and received calls asking me to explain what I have already explained, but until today my queries have not been resolved. Right now I have reference numbers ***NF and ***NF, and I guess I'm gonna get get another reference number for this query as well. COULD FNB HOUSING FINANCE PLEASE EXPLAIN WHY THEY ARE DEBITING MY ACCOUNT ABOVE AND BEYOND WHAT WE AGREED FOR AND STOP GIVING ME REFERENCE NUMBERS. Is your staff so *********** that they cannot even explain what they themselves did to my account?