Coupons requiring a smart phone.......🙄

So I get a customer today giving one of my cashiers in training a hard time. This was her 2nd day on a register, he brought up 3 of the 16.5 Oz six packs and got the discount for them. Apparently you can get another 1$ off if you use the coupon from our store app. He brought in the sales ad, which clearly states that. I read it to him and explained myself and the reason why it didn't reflect that during checkout. He said he didn't have a smart phone and understood. I went to check him out again and went through the whole thing again..........😑. He ends up saying "THE HELL WITH IT THEN" and storming out. I had several customers waiting in line as this unfolds. It kinda embarrassed me and delayed several people in line. I can safety say now what I was thinking.......YOU FIRST, YOU OLD ORNERY BASTARD, AND YOU WILL WISH YOU PAID THE 1$ FOR YOUR DR. PEPPERS. BET YOULL WISH YOU HAD THEM......😁