14 DAY TRIAL // Blizzard has been sending new keys for their closed Hearthstone beta test on a frequent basis. They have recently uncovered a bug that prevented some users who opted for the close beta from receiving their game keys.
Their ultimate goal is to invite everyone who expressed interest in the closed beta before beginning the open beta phase.
“We recently discovered an issue with the beta opt-in process where the opt-in selection setting for Hearthstone (and Heroes of the Storm) may not have been saving properly for Battle.net accounts with no game licenses attached.
This issue is now resolved, so any beta opt-in selections going forward should save properly in your Battle.net account,” read the official announcement on the Battle.net Hearthstone forums.
If you opted into the Hearthstone closed beta, make sure you're checking your Battle.net account's email address, GamingBlend advises.
Blizzard is periodically sending new invites to both North America and Europe, as can be followed on the game's Twitter page.
The company also recommended that users not impacted by the issue go check their junk and spam folders as well as the Promotions tab, for Gmail users, as beta invite emails have been known to end up in those locations.