FNB Con-Story

What con-story. I paid my loan account in full the complete balance of R 30,988.00 on the 10 September 2019. I get an sms earlier today to say that my account has been debited with R 617,00 to the personal loan account I paid off earlier. There was an email I sent to my Premier banker on 5 September 2019 and after several emails tells me I must call them myself to cancel the personal loan. What do I pay the premium for? I call them now and they tell me that the amount that was debited to my account will take 7-10 working days to pay it back. They are quick to charge interest, late fees (not guilty), and other charges that may pertain to the loan or account on that specific day it is due, but it takes them 7-10 day to pay it back. In that that time they earn interest on that money before it is paid back, stuff the client.