FNB put a hold on my funds

FNB I'm not happy with service at all. SARS has paid my refunds following an audit which found in my favor (completion letter issued). Payment was done on the 20th Jan 2021 into my business account, yesterday the 21st FNB put a hold on the funds. SARS did not sanction any holding of funds. Please can this hold be removed ASAP coz it's unacceptable and extremely inconveniencing, the business is replying on this money to review following knocks suffered from this Covid-19 Pandemic.