FNB Holding funds even after release by rental company.....

Fnb Credit Card division have not released a hold on my credit card even though the company in question released the hold of funds on the 9th of October 2023. The hold was for a rental vehicle which was returned on the 9th of October. I have had numerous phone calls which required me to send letters. I have done so, only to find more requirements. The bank is holding my funds and said that they would hold it for 38 days. This is not acceptable. The rental company cannot send letters containing my financial information as it is not their protocol.