My late Granny refund

My Granny passed on last year October. She Lived at Musgrave park for over 20 years. She had an interest bearing account with these people. I've sent someone working there Rushaan Ariefdien 8 emails she has rep**** 5 times not 8. The answers are all 1 liners. I received all formality emails no detailed explanations of anything. The main highlight was if I don't get all the documents then bye bye refund. I asked for an accumulative amount that is owed to my late Granny. They sent me which I can only assume is a snip from a spreadsheet with cramped columns therefor I cant see the dates over the period for which the interest was received. I cant see if its over 1 year or over 20 years but they not answering me fully. I get stonewall answers or no answer. I was told upfront without all documents its ******** to refund my mom the money - which I understand I got 95% of the docs just need letter of auth but I want to know what the amount due is so that I can figure out if its worth my time and money to go to court and get one but its starting to sink in that my mom is never getting this refund.

I've posted this on Goodfind properties as well I see you guys have the same website so I'm assuming you are affiliated.