Fnb Quicksell what they don't tell you

I have had an home loan with fnb, the property was later sold on Fnb Quick Sell around 10 years ago. Before signing the otp with the estate agent I phoned into fnb home loans and I specifically asked them if I accept the offer "what will my shortfall be" the representative from fnb informed me that it will be R100k I then made my desition and I sold the property over the fnb quicksell platform. The issue comes with the following when the property registered in the new buyers name and fnb placed the shortfall on a personal loan the amount was not R100k it was R200k. This is not acceptable and for years that bad dept has hampered me and is always showing up on my name with the credit beuro and ITC. This hampered my financial well being not being able to open any form of accounts nor being able to purchase vehicles and so on. Today I phoned into Fnb home loans again.... 2 time the respective agents hanged up the phone before I was finished to introduce myself and asked for assistance, I phoned again and they informed me that there is no call Centre for this I should send an email stating that they work differently. I want to be able to speak to a person. And be sure definitely when you sell over fnb quick sell you do not truly know what you are letting yourself into.