Blocked accounts due to "Expired" proof of residence

FNB has sent me an email requesting KYC documents (Proof of income proof of residence etc) I cant seem to fathom, as I have submitted all these documents when opening the accounts! I have sent these documents through when it was requested months ago. And now they have blocked all of my accounts. RIDICULOUS. I have called their premiere banking this morning spent 20 minutes on the phone being transferred from one department to another. Spoke to 4 different people just to be told that my proof of residence has "expired". How does that work? I have sent a proof of residence to them recently and had no idea that it could expire. Your service is ridiclous! My experience with FNB has been horrible recently. Its one thing after the other and the customer service is ALWAYS TERRIBLE. I WILL definitely be switching banks ASAP!!!