...when I asked the assistant if an American 6 was a 12 and she said yes, when in actual fact it was a 10.
And I had 6 pairs of jeans in the changing room that I could squeeze into but would no way buy as they were verging on the camels hoof (iyswim).
FGS 
What a waste of my frigging lunch hour. Surely they should know their sizes?????????