Horrible service - packer chancing prices

<p>I went to buy baby powder 400g as advertised i expected the sale to end in Sundays however i picked 5 only to see a packer tell me its not on sale and has no price on the shelf she then takes the price tag from the 500g and puts it in place of the 400g - i tried to dispute it had no price and i took it for granted its on sale the manger never came to assist as my point is the packer changed the price </p>