false advertising and unhappy customers

my husband got an email yesterday from takealot giving him a r150 coupon, minimum spend, r500. He wanted to buy a puzzle toy for the dogs that was on a very good special, and something else, However, when he checked out the items and added the coupon, it now said this coupon is only for a minimum spend of r750. Not a good way to do business I would say. We ended up not buying, as we don't have that much to spend on items at the moment. If takelot is trying to get customers, or to give them a treat, this surely is not the way to do it.