FNB Business accounts frozen *******ly and with no justification

For no reason and without any justification FNB froze some of my business accounts. I do not us overdrafts and have positive balances in all accounts. All my Fica stuff was up to date. A law unto themselves Have requested official apology letter and considering closing 22 business accounts over this poor conduct. What message do my suppliers get when I advise them my bankers have frozen my accounts and I cant pay them. Certainly not a positive one