Fnb refusing to refund me

I deposited money to my fnb loan account to try and reduce the monthly payment or installments. This was on the 6th of June, i assumed the amount will be automatically added to the loan and the loan amount would be reduced. This didnt happen so i called the loan department and the consultant didn't give me a clear explanation, they further told me that i could be refunded the money which i kindly opted for. On the 4rth of a request was sent to refund me and i was told this would take 3-5 working days, come after those days no more from Fnb. I made a follow up call on the 14th of July and i was told my details has been forwarded to admin and i would be refunded withing 24 hours, that didn't happen. I made another follow up on the 21st they told me the same 24hours story but still i haven't been refunded. I asked the consultant whats the reason for the delay and they didn't have a reason all they told me was admin is the one in charge, i asked for the contsct details for admin and they said admin only has an email. If a debit order went off my acc and i didnt pay fnb would put interest on their monies yet they are holding my money and making profit of it. I don't think this a good way of doing business especially from a bank that know hows important money is. I have spent more that R400 contacting the FNB call centre wich hasn't been fruitful, in essence they owe me momey and im incurring expenses because of them. Come the 29th and i dont have my money i will be changing banks and not paying the stupid loan. Enough is enough.