haressment and incorrect billing

Its very hard to believe that a Finance company can hire very rude consultants that have no regard for the human race. My car was a month behind in arrears and I made arrangement with one of the collection agents. I was later called by someone called Sema who had no regard to hear why the payment for July was broken I tried to explain that I lost my job in April and didn't get paid. To cut the story short I got a call on the 26 August advising that my car will be repossessed if I don't settle the arrears in the next three days.The arrangement to pay 4400 had been cancelled. I was advised that once the arrears are settled my account will be up to date.Then the normal debit order of 3200 will run normally on the 31st.To my surprise I paid the arrears I was owing on the 27 Aug.I left 3300 in my account for the normal instalment to run on the 31 August. NOW MFC DECIDES TO DEBIT 4400 PUTTING MY ACCOUNT IN A NEGATIVE BALANCE AND CAUSING MY OTHER DEBITS TO BOUNCE.UNACCEPTABLE.This was not the amount agreed , funny how quick they are to demand cash &amp