How to block communication from another player in Diablo III.
How to report a bug in Diablo III
Player reports they had heroes they use to play in Diablo III and they're now missing.
It is not possible to merge the progress of two or more games into one.
These errors can be caused by temporary server issues in a specific region.
This article explains the process of speaking to a Game Master (GM).
How to obtain error logs for Blizzard games