i know they have them donated , i have sometimes seen one or a few lycra skirts in black bin bags in the store room when the doors are open ,but never see any on display .
Well...maybe the staff do not think they will sell and send them to the rag man.
If i were you i would have a word with the shop Manager and maybe ask him/her to look out for some for you and put them to one side if they are ragging them.
