False advertising

I found a R99 contract for 20GB a month including a router in the promotional pamphlets of Game earlier this month. I visited mall@carnival branch on the 21st of April and was told that they don't have stock and should try at another branch. I then proceeded to try buy a deal which was R119 for 20GB a month including a router with the possibility of a showmax voucher, and was once again told they are out of stock. I have since then phoned the Eastgate branch and the mall@carnival branch again with the response the same as before. I was further informed that they would only get stock by the 6th of May, when the deal actually expires on the 3rd of May. I do not understand how a major retail store such as Game could advertise two deals and then proceed to have no stock for the entire duration of the promotion. If a deal is advertised for a certain amount of time, as this one was (20 April to 3rd May) how can you waste the time and energy of clients by actually not offering this deal in stores?