FNB close my father's account even after the lawyer's gave clear instructions not to

Hi I would like to report that as a FNB customer I'm not happy my Father's account that he shares with my mother is frozen since my father has passed they reported the estate as late but we gave them clear instructions not to close the spouses account that he shares with my mother we send FNB a clear letter with those instructions by our lawyer but they still closed it so now we can't get access to the account we need to buy for bills and clearly we can't because the account is closed but money is still coming there please help