Welcome, to the confusion of why blizzard will not let GMs address this case-by-case provided players have the dates for achievements.
With every player affected writing multiple tickets, it simply costs them more in time than to just fix, and they could have the added benefit of some player approval.
Anyway, for your information see the following threads:
German (Had BLUE post!):
The blue post basically said: An enchant or weapon with it on can be used as proof; and to post on forums and also report on Twitter or submit a suggestion in the game
EU:
US:
And the one Datara linked above.
4-5 active threads with 100’s of posts, twitter posts, tickets and suggestions…