Red Listed

I'm an ex employee ...employee number *** I had been employed from 2012 till 2019...last year I experienced the worst kind of mistreatment from Fnb which today continues to torment me... I became sick had an ear problem I notified my BA... it continued and had to go home and I went to see a doctor so she could check it out and give me a sick note ...The sick note only gave me 2days ...16 and 17 April 2019...while all this is happening My father was sick and fighting for his life in hospital...My BA kept pushing for me to send the doctors note while I was at home...Seeing the situation at home I couldn't go back to work I altered the note to 18th and sent it via whatsapp to the BA that kept pushing for it...My dad passed away on the very same day i sent the letter the 17th...n was buried the following weekend...I went back to work to find I had a case for altering the doctors note which I never denied and stated the reasons for my actions when asked to write a statement...My BA and Manager sat me down and told me of what was to follow...I told them Im not emotionally well I won't be able to attend hearings and decided to resign with immediate effect...Even with that said I was told the case was going to continue in my absence. The Manager came to my place to hand me the letter to attend the Reds meeting as I was being charged for dishonesty which continued in my absence as well. A year later when I go for employment background checkups I discover I was red listed by FNB and can't be employed in any financial industry... My life is stuck cause of this as I cant assist my mother with anything...as the only experience and qualification I have is with the banking industry...How can I clear my name from that register??Is there a certain period one has to serve or is it a lifetime thing??