False Advertising

I went to Jet stores in Ermelo Mall to do some spring shopping. I thought I was very lucky since they had posters and adverti*****t displayed all over the store stating 50%of all sale items needless to say I spent an hour "shopping" and then another 20 min standing in a queue. When I finally got to the cashier I mentioned that I think the sale is great only to be told that the sale ended and that I will not get an additional 50%discount. I asked the cashier so why do they have the posters on I even stated that this is false advertising she responded with "I don't know" time wasted in a store with pathetic service the manager did not even try and assist or apologize...