ABSA The ****ed up bank

its been 3 years waiting for Letter of Authority for my dads Will but still nothing. the only thing we got was execution letter which every company rejects. There were funds in my dads account but my mom was told that the money was used by Absa, for what reason we dont know, they dont even want to take accountability towards that. Since Absa/ employees stole my dads funds, can we at least get the Letter of Authority or you also want to ***** his property?