Late Son's Frozen Bank account

Absa Bank has frozen my late son's bank account and I can't access the funds that were left on the bank account and when I consult with them I was told to submit letter of authority, Death certificate and my ID documents. It's been 3 months going back and forth with this bank and till today am still not getting any help and wondering whether will I ever succeed in getting any help. It stresses me because I have spent a lot of money trying resolve this issue with Absa Secunda Branch, Mpumalanga. My late son name is Bafana Nestar Mkhabela, ID Number: *** 082