Woolworths and pricing promotions

I was standing in woolworths melrose arch on sunday afternoon in an area marked at 50% off - I had just taken a pair of jeggings to buy when a shop assistant called Neo came and removed the marketting material - I asked fòr a dispensation as I was already in the store ànď had the pants in my hands. Neo said they had reçeived an email that morning that the promotion had ended and that head office controlleď the pricing remotely. I have never heard of a pŕomotion ending on a Sunday and I fail to see the relevance between morning and afternoon when the marketting material is still up ( which is ******* and is known as false advertising). I am upset because I wrote to Woolworths about the false advertising and never even received a response.