What to do if a gift purchased in the Battle.net Shop was not delivered.
This article highlights a few passages from the EULA that are most relevant to this policy.
How to attach an Authenticator to your Battle.net account
Troubleshooting steps for linking a Twitch.tv account with a Battle.net account.
Troubleshooting steps for if you can't claim a gift
What to do if you placed an order for Call of Duty: Modern Warfare 2 but it didn't go through.
What to do if you are missing rewards for completing chapters of Hearthstone adventures
How to resolve this error in Call of Duty: Modern Warfare 2 Campaign Remastered