Embarrasment over false advertising

I went to Miladys for the 2 for 1 jean sale. I took a boyfriend jean and a cropped jean off the same rack that was advertising the sale. I also took some pants and tops for myself. When I got to the till, I was asked why I didn't get jeans from the promotional rack as the cropped pants were not part of the promotion. I explained to her that I in fact did get it off that rack, she told me that maybe a customer hung it on the wrong place and that the racks were a bit messy. When I insisted that there was more than one of those on the rack, she called the manager. I showed here that there was a whole range of different sizes of the cropped jeans, she understood what I was getting at, and was prepared to give it to me on the promotion. The both of them were then informed that it had to be jeans from the profile to qualify for the promotion. If your staff and managers don't even know what the T's and C's are, how do you expect your clients to know. Only when arriving at the till with a queue behind me, did we realise that I had to pay full price. Needless to say it was very embarrassing. In fact, I cancelled the whole transaction. In my eyes - false advertising. Both on the same rack.