I signed up for the Music Pass thing, paid the $10 bucks, and it doesn't appear anywhere. In fact, it prompts me to pay again even though they sent a receipt. Ideas?
Give it time to update. It doesn't appear anywhere other than in your subscriptions section on your Microsoft account. But you will be able to download music from the store. It usually takes a few hours to sync with the payment section, just keep periodically trying to download a song from the store.
I had some issue when it switched from trial to paid mode where my phone couldn't use any of the songs I downloaded through Xbox Music Pass (or download new ones). Everything was fine the next day.