FNB Home Loans - Wrong Advice - Our Problem

We activated a flexi option on our home loan some time ago. We then noticed that money became available so we decided to contact FNB Home Loans to confirm if we may utilise the money. We spoke to an advisor who confirmed that we could use the funds. We then proceeded as we were told. The following week we received a call from FNB Home Loans to ask us why we hadn't paid our home loan and that R10 000 was outstanding. We explained what had happened, that we used the cash as the Advisor had told us to. Surely the transactions and payments reflect on their system? How can they accuse us of not paying?! They then said we have to pay R10 000 or our home loan account would be in arrears and adversely affect our credit rating. We panicked as R10 000 is a lot of money. I had to take a loan from my employer to pay into the home loan account. This same R10 000 will now be deducted from my bonus - the entire amount! Why are we being penalised for the wrong advice given to us? We've laid a complaint and are yet to receive a formal response. FNB are quick to phone us to wrongly accuse us of not paying but now that the fault is on their side, its weeks gone by with silence from them! This is absolutely disgusting service. This is FNB'd fault and they need to fix it immediately!