HOLD ON ACCOUNT WITHOUT WARNING

I have had an FNB bank account for almost 2 years now and this morning when my salary was still not reflecting in my bank account - i phoned the bank just to find out that they have put a hold on my account because of outstanding paper work - when i asked what paperwork is outstanding the lady at the call center could not tell me - this needless to say happened without any warning like an sms or a call or an email. now i have to go into a bank to get the hold of before i can get my salary - i think this is really bad service. they can send adverts but they can not let you know that there is outstanding paperwork on your account - how does this work?