False information on prices

I saw House of Coffees Special Blend priced at R81.99 for 1kg, but it was actually a 500g product. Lots of people actually look at the information on the price tag that Pick 'n Pay puts up (the summary of price per kg etc.) as a quick way to determine which product is more cost effective. I urge all shoppers to ignore this false information - The tag stated that the coffee was effectively R81.99 per kg when it was actually R163.98 per kg. Sneaky move by Pick 'n Pay since they were probably trying to get rid of old stock, and many customers would trust that information. The manager told me that it was a mistake and I cannot get 1kg of the coffee for R81.99. Would pick 'n Pay care to honor the information that they display on the tags or should we look to competitors who don't try to trick their customers?