Help: the MR update has disabled my phone

Well, I went and installed the 10.1 MR update several weeks after it first came out, assuming that whatever bug was in it would be fixed by now.

Nope.

I now have a phone that:

- does not work as a phone
- has deleted all my old text messages
- says it is running at 10.1.0.273, despite me downloading and installing 10.1.0.481

What do I do?

Yes, I tried to create a backup just before downloading. Now BB link is saying I only have one backup, from several months ago.

I give up. This is utterly senseless. You can't protect yourself.

Help.