Bad service

I am really disappointed that my Cheque account I have since used it 18 months ago when stopped working. But FNB can see that there is not funds going into the account and they just continue to add bank charges and the worse part handed over me to the debt collectors. I have been with FNB my whole life, all I need is for my account stop accumulating bank charges, as I am willing to make payment arrangement if the account get be closed or downgraded to Easy account while making payment into it.