Mr RG Anthony vs FNB

Hi I have had an account with fnb for a long time. I had money taken out of my account last year and I went in too inquire about it. They gave me forms to fill in to investigate it and I was told it will take about a month to sort out. It's been almost a year now and my account is now closed and I'm now getting calls from fnb that they going to hand me over to attorneys and it's effecting my credit now . I'm taking my business from fnb now as I can't go on like this anymore. Can anyone advise me please.