Frozen estate account

I had a lovely interaction when I got assisted by Martha from FNB Jabulani mall when I was opening a deceased estate account. What I would like to understand is why I'm unable to access the funds because the account is still frozen, while Master's office is still verifying my documents, yet the letter of authority has been issued and in my possession? This makes me have second thoughts about FNB as it comes across as a delay tactic. Kindly follow up and advise?