FNB most devious bank

I have found FNB are devious,who is always aiming of reaping people off and *****ing money from their pockets any how.. i had a bank account with FNB few years ago which i closed the account few years ago.Without me being aware the account was still open which it was accumulating interest.FNB never contacted me in any form to highlight to me the account is still open and accumulating interest.They can see in their system the account is not active at all but they kept quite because they knew that at the end of the day they are going to hand over my name to the debt collectors and blacklist me.MBD is chasing me to pay R5552.50 immediately and failure to pay as requested could result this being handed over to attorneys for collection through the legal process.Why this bank always look for victims and destroy people like this,me being a single parent every cent count now i have to find myself have to pay the debt that has been throw on my lap like that by this selfish rootless bank who enjoy blood money from innocent bread winners.Im so disgusted and furious by this ******* from FNB Bank.Can someone help me as i wont be able to pay R5552.50 immediately??