today it wouldn't load any longer, claiming "something went wrong", and asking
me to try again. I did, approximately a million times, both on Wifi and 3G.

So I started chatting with a guy called Rahul over their website. Rahul advised me to
reinstall the app, which I did.
Subsequently, when trying to associate my phone number with the app upon first
start, I was told that the number is invalid.

Rahul suggested I poweroff and remove the SIM card, which I did, but
(obviously) that didn't fix anything (because why would it)?
For the record, I used Android logcat to look at the debug output, but there
is absolutely nothing being reported for when either error occurs.
What should I do?