FNB Froze my account

Last week I received my mom pension fund money and FNB froze not only that amount received but the whole account. That's my day to day account. I have provided proof from Old Mutual stating that the money was from Provided Fund. I'm from the branch and they called the ***** call center to confirm that they have received the letter, now I'm being told I need to provide a Will. The terrible service I've received from FNB weather by going to the branch, secure chat and call center is the worse experience ever. Tomorrow is the 25th my debits are running and my account is still frozen. I want to close all my accounts I have with you soon as I can access it. The account was frozen without even giving me a heads up. I just want my account working again so I can move to another bank and close all my accounts with FNB. I'm telling my husband to move his also including the Home loan and all the investments account