Thanks for taking the time to post to our community! Let me see what I can do here to answer all your questions.
1- To me, this sounds like an issue on our side where your phone number and online account have not been fully linked. For this issue, we will need to speak with you over the phone so that we can get a help desk ticket opened up with our web support team.
2- Do you by chance have a prepaid account? If so, the T-Mobile app is not available for prepaid accounts at this time but we will make it available as soon as we have fine tuned the experience.
3- This sounds more like a browser cache issue where the links you are clicking may have gotten mixed up. My suggestion would be to either try clearing your browser cache and cookies or trying a different browser.
1. I'll call when I have some free time
2. Yes, I do have a prepaid account.
3. I have tried multiple browsers on multiple devices, nothing is working.