FNB withholding funds

I want to share my absolute frustration with FNB. We received a refund from Sars and then without any notification from FNB they decided to place a hold on the amount received and when I enquired about this they said that is what they do and call it a verification. Sars won't release any money into my account if the details are not correct then why does FNB not believe that the money is for my account. With my previous bank this was never the case. And FNB says it will hold it for 48hrs to verify. I just can't believe this. Take money without giving us notification first. Perthetic service.