No help for deceased loan holders children

I lost my mom in 2019 who had a bond account with Nedbank, I called them to notify them of her passing and sent through the relevant documents. No one got back to me, I would call and call and the phone would ring off the hook, or when I did get through the deceased estate department, the line would disconnect before getting real assistance from the agents. I continued paying for the loan as we did not want to lose the house. It's now been paid off and we need to close the account and account afford to appoint a lawyer to get a letter of executorship. No one is able to help us or freeze the account while we can sort that out. Consultants at the branch are not clued up about the processes I had to ask around to find out what is needed.