Standard Bank blocking funds with no reason

Standard Bank is the worst company I have ever seen. Very insufficient service I have ever experienced in my life. I made a pay&clear payment through FNB account into my site manager’s Standard Bank account so he could pay employees on Tuesday. Standard Bank froze the account and said they request an email from FNB ***** department to their Standard Bank ***** department confirm that the funds are indeed from me. FNB refused and says they can’t issue such email, the only thing they can issue is a proof of payment. I made unlimited calls and today is Friday and employees are not paid because of this useless bank. They don’t even want proof of payment and funds are stuck.