How to report a bug in Diablo III
What to do if you are missing the achievement "Heroic: War is Hell" after winning a warfront and completing the quest.
Information on reporting incorrect rankings in Overwatch
What to do if you can't find or start this quest.
Information about being unable to trade dungeon/raid/instance loot to another player
デスクトップ版Blizzard Battle.net AppとBlizzardグループでの発言禁止に関する情報
World of Warcraft couldn't locate a game account for its region.