I apologize if this has been answered before, I checked the achievement triggering thread in the achievements forum, and I also browsed there and here to see if anyone else has asked this.
My filled wardrobe achievement has been stuck on 6737 for awhile now. There's 100 items on each page in the wardrobe, and I have 67 full pages of items, plus 79 items on the 68th page. That should be 6779 items, which is more than my achievement is saying yet I can't get it to update. What do I need to do?
There is a thread in the bug forum - Filled Wardrobe achievement not triggering in new wardrobe
Long story short: Its a known problem for everyone. Bug has checked it out to see if it can solved quickly, it can't. There are other priorities and will be looked at when they get the chance.
If you post in that topic, you will get a ping when staff post there "officially" - so you might want to read up on it and post :).
In loving memory of Need posting achievements?Then join Posting Frenzy Achievement Items - searchable list List of Borders and cutouts New at Fresh and Flavorful Ping Group