[2020] Requesting Help: Getting emails for my other account on one email.

So I have multiple runescape accounts which I created at some point, and only use maybe one or two of them. I have one account whose name we will say is Bob and another whose name we will say is Joe. I got an email regarding Bobs account, the problem however is that I received the email at the address that Joe is registered with. I expect this is because the email I used to use for Bob is gone and deleted if I remember correctly. I discovered this by receiving an email a few weeks ago saying that Joes account got a password reset request and that I should change my password, so like a good boy I went in and changed it. I remember specifically it gave the message saying "Dear Joe we have received a...bla blah blah..." and now a few weeks later I noticed I got another email just like it, except that it was for Bobs account saying "Dear Bob we have received a..."

I'm not entirely sure what to do or what I even can do. The email for Bobs account I lost, and I have an Authenticator set up on it apparently. My best hope is that I still have the Authenticator code on an old iPad, but even then I don't know what I should do. Is there any way I can stop this? I wouldn't mind just terminating Bobs account all together honestly. I'm also curious that it might be a phishing scam or something because when I log in with the email address that is receiving emails for both accounts, I only see joes username, and can't see anything for Bob.