MTN False Advertising

MTN sends us a message so my wife can upgrade her contract. We walk into an MTN shop, take the book with their advertising and give our request to the manager. After going halfway through the motions they all af a sudden that the deal is R100 more expensive. This is false advertising and I suggest that they continue and give us the deal as advertised. They apparently had 14 days in which they could have corrected the error, crossed it out in every book to cover a printing error, yet they chose to continue with the false advertising. This will also be taken up at the consumer board as blatant false advertising. I will expect them to honor their advertised price and package