FNB Pledged SARS Refund without my knowledge

My SARS refund has been reversed without my knowledge from my account and I had to contact FNB to find out why. I reached out to SARS and they were unaware of any pledge against my refund. I have email both FNB and SARS with no luck. Very frustrating that nothing was communicated with me as a premier client I would expect this to have been shared with me.