To log in to the Gear Store you must have a Gear Store account different from your Battle.net account.
What to do if you do not have a Battle.net account but are receiving emails from Blizzard Entertainment
This article explains the process of speaking to a Game Master (GM).
Cannot install or Patch Call of Duty: Black Ops 4
Troubleshooting steps for resolving payment error in Heroes of the Storm.
How to read and analyze WinMTR data in order to track down a potential connection issue.
How to update your BattleTag.
Troubleshooting steps for error "Game Initialization Failed" when launching a game
What to do if you have not received the 20 tier skips from the Battle Pass in Call of Duty