FNB withheld my funds from me without my permission or bothering to inform me

I've always supported FNB as the best bank in SA. Until they decided to put a ***** hold on my account without bothering to inform me, because it's apparently not "required". In essence the services I paid for are withheld from me without my permission and without informing me? I have the app, they have my number, I even logged into my banking online and nowhere was I informed that my account had a ***** block. My account was completely frozen without me being informed and I'm told that's their policy.