FNB changed system and locked me out of my account (without telling me!)

I am unable to access online banking on either my computer or my phone.

I asked FNB what was going on. This is the explanation (I have copied and pasted it word for word):

Kindly note Online Banking has migrated to a system called Single-Sign-On, meaning customer will only logon via their personal Online banking profile and then select the profile they need to transact from. Your personal profile is blocked and needs to be reset as per the steps sent. This migration app**** to both browser and App login.

After about 10 emails to various people at FNB, I'm still locked out. No one is coming back to me. I have not been able to access my own money for a day and a half. It's incredibly difficult to run a business under these circumstances.

I cannot believe that FNB makes such a HUGE change to their systems and doesn't communicate with their customers. This is a massive disappointment. I need a new bank!