Terrible service

I have a pending autorisation on my account which apparently according to FNB is a non copleted transaction/ incorrect OTP or details. But thet CANNOT tell me what it is for or which company. I have made no less that 15 phone calls to different departments and been on secure chat foe 2 hours with no joy. I have been told i must fill out a form that no can tell me where to get it BUT i need the vendor details which i do not know and FNB cannot tell me. So the funds will just stay in limbo until the vendor queries it, if ever!!!!