The best way for forums users to get support is to do so here, by PMing me.
If a world is involved please say who owns it.
I will probably want your support ID, which is a piece of confidential information you should only share with myself, Dave, or Noodlecake Studios, the Android team. It is located in the SUPPORT section of the HELP/CREDITS screen, reached via the in-game pause menu.
In-game names are the names you connect to worlds with, own worlds with, and with which I can easily locate your account.
Rollback availability is dependent on how active the world is, how far back you wish to go, and whether there have been major technical issues with your world or not. While we take backups daily, worlds that remain unchanged from the previous day’s backup will not be backed up again until changes are made. We keep a limited number of backups per world. This means that the less days your world is actively in use the more likely we are to have older backups. As such, if a problem occurs with your world you might want to whitelist it to yourself, password it, and stop visiting it until it can be dealt with.
With Android-specific issues I will probably refer you to Noodlecake Studios for support. I can help with general Blockheads stuff though.