FNB and false marketing

So FNB uses false marketing to make people use their products. I was a using a Private Clients Debit Card and had a Credit Card. I was then sold about FNB Fusion Account, an account I was told acts both as Debit and Credit, if you deplete the debit then it automatically goes into Credit account. This was just a lie. I am in a situation where my company can only pay me on the last day of the month because I have resigned. I was therefore hoping I could use this system when my debit orders go through. When I saw this was not happening, I asked to cancel the Fusion and go back to normal Debit account, I was told that I have to settle the overdraft I have on fusion. Mind you, the overdraft is from the initial debit card and it was transferred smoothly to Fusion. I asked why it can't be transferred back to Debit? why was it not an issue when transferring to Fusion but it's an issue now? I was told I have to pay early termination fees etc? wow . My plan is to really settle my account then leave FNB and go to another Bank.