FNB FAILING LONG STANDING BUSINESS CLIENT

I sold my vehicle to a Dealership and was paid into one of my FNB bank accounts. FNB raised a concern for a large receipt into my account and requested I furnish them with documentation relating to the sale and POP etc, which I did a week ago. This morning I am now told that they cannot contact they FNB client who made the payment to me and I must now get additional documents from them. I was surprised to find that despite a week later my funds were still not accessible to me and I was to get additional documents. Yet there is no concern of my prejudice to access my funds, nor any courtesy that I must get a hold of their client as he was not responding to their calls and emails. So if he does not reply to them my funds remain frozen. Does that sound like a bank that has your interests at heart?