I changed my HA then went to search the user shops for an item, and got the 'Lets get some shoes' achievement for having "at least 50 items for your feet layer". I only have 12 items in the 'feet' section of my wardrobe.

file a ticket! go to the bottom of every page and click "Contact Us" or on the top menu bar: Subeta > Tickets

: As said, please file a ticket. :)