Matt, I have been a Sirius subscriber from day one. However, I don't use the app because my truck stereo is great (and that doesn't help you).
Did you go to the app developer webpage?
Try emailing them again, if you haven't. Calling Sirius for any reason is like talking to a brick wall and sometimes when you email Sirius Cust Support, their reply emails read like they were written by a brick wall, but keep trying.
That is what I have done for other issues.........kept trying.........and I eventually either spoke to, or was emailed by someone that knew what they were doing.
No, Verizon won't offer any help as it isn't their app.