I have all the required items in my wardrobe but the achievement still hasn't been given to me when it says I have all the required items in my wardrobe.

For how long did you wait? It always takes a while for the achievement page to really update (I had the same problem with the other lifelike achievements) and try this: go to your achievement page and then click on the neela achievement and view how many neelas you are missing (there should be green checkmarks since you have all of them). Then you should get the achievement (this worked for me)

Thank you for the help :) i'm still fairly new here. I just checked and it was granted :D