There are actually 9 Quests played over 8 different Story Mines.
The Achievement of King Of Hearts requires you to collect a minimum of 76 Ace Of Hearts card (Event Special Items).
You can gain a maximum of 68 Ace Of Hearts cards from the 8 Story Mines.
So you need to collect an additional minimum of 8 Ace Of Hearts cards from the Challenge Mines.
If you put up some screenshots as previously suggested....we would be able to see what gold achievement you are missing 👀🤓🧐
Have you checked out the links that were previously provided above????