Half Price for Half Measure

So it is Easter and stuff at Half Price Both Tescos and Aldi's advertidsing Leg of Lamb at Half Price but they have issued you and the TV adverts with 0.5kg pricing which is wrong!!!! People get hopes up and families of Lamb and get to a shop to find the lie and may end up buying what they really can not afford to save disappointment at home. Please make them submit data in a comprehesible format.