What actually happened was the girl told me the item I got was size XL as I did'nt have my glasses on, that was the size I needed but when I got home I discovered it was size large and I would'nt have taken that size if I had realised. So really the girl did'nt know her sizes. She probably got mixed up. I don't want to make a big deal about it but just wondered whats the situation generally is there.
I may be a little late with this information.
If the shop assistant gave you the wrong information 'provided you asked her advice or opinion' then the shop would bear some of the responsibility.
An exchange or credit note will be a fair solution. You might have difficulty proving you asked for her opinion as to size.
Good luck browtal