FNB Homeloans Debiting too much

FNB Homeloans debiting over R10600 off my account instead of what is owed (R800). When speaking to them I apparently have to wait 5-7 working days for my funds to be returned. However 8 days later, now I need to fill out a refund form?!!! Why do I need to jump through hoops because of a problem FNB has caused? Do you treat all your customers this way?