False advertising

I received a message stating spend R350 or more and swipe your xtra card and receive R50 off your purchase before the 7th of July hence decide to take the opportunity and make use of it however I did not get the discount or anything the manager from the cornubia stores contacts the the xtra they advise that they will contact me as they having a problem with their system this was on Saturday the 3rd of July however no correspondence has been done I firmly look at this as false advertising or marketing