I unlocked an achievement that I wasn't completing

I was completing the achievement 'Tie Dye Outfit' when I received two notifications. The first notified me that I had completed the achievement 'You Need a Mint,' which I wasn't working on and had never completed. The second notification informed me that I had completed the achievement I was actually making ('Tie Dye Outfit'). Also, the top ('Tie Dye Tank') that unlocks upon completing this achievement has still not been unlocked for me.