Bad service

I took out the deal between istore and FNB where after doing a straight purchase FNB would change it to a budget and deduct R699 per month and this was meant to be done within 3-5 business days which on the 5th day I enquired about it with FNB and they said the transaction hadn’t even been loaded they then loaded it but no balance was made available today when I called them they said it’s tough and I must wait another 3 days because of the mistake made by them when I asked for a supervisor / manager I was given an incorrect email to send documents to so that I can resolve this