Won't the accounts you've communicated with before save the history of their correspondence with you? I mean, you should be able to see it. If the history is deleted, then the deletion is already an alarming sign. Why would a person delete the history? Dad, Mom, the way you write and scare people, they won't delete the history.
Also, I'm not sure if I understood you, but you're again claiming that a premium account subscription is completely nonsense? I've been using it for a long time, and in addition to the convenience of translating from different languages, there is a function to block all other accounts that are not on your lists. Fraudsters who bought a premium account will be able to write to you. This is, of course, possible, but it will be quite expensive for them, and they can be identified since they pay for their premium with a card, the details of which can be found out.