fnb complaint

i am jacob from gauteng having a headache about a confirmation letter i requested from fnb.i had a bond house with fnb from 1996 to 2003.i was dismissed ,my house reposessed and auctioned.in 2019 i went to fnb banch in Krugersdorp,Johannesburg and lastly to fairlands but promised to be helped,This confirmation letter is very important as i desperately need it as of yesterday.To my suprise i was told i owe bank R63 000 of which i was never ever told or informed about before i went to request confirmation letter.I am a married unemployed father with kids to look after.If i knew about the balance before 2010 i at least would have setled it.I was also not told as to how much was house sold for.Can you kindly help me with this letter as i desperarately need it . yours sincerly jacob ***