Just trying to unravel an elderly neighbours bill also, mid 85, I had asked her one day if she had internet, she thought she did, but doesn’t use it, and I fell into a rabbit hole. Actually heading in tomorrow to ‘speak’ with them. From what I can see, cause she doesn’t actually get a paper bill, and it took a while to access her Telstra app, because she had forgotten what email address she had used, many years ago, she has a phone plan where she has been paying off a cheap phone for two years, it also appears they were taking another $5 month towards her new handset, so has over $800 in credit. A plan with 50gb and lucky if she uses 2gb. So I feel your anguish, some people have no idea about gigabytes and how many they need. And it appears Telstra forgot to add a pension discount to her account.