Stop and Shop complaint: Digital Coupons

I went to the Stop and Shop grocery store on Union Avenue, Haskell, NJ tonight to purchase ice cream. The sign said 2$4. for Turkey Hill Ice Cream with a digital coupon. I went to the customer service area and asked the gentleman to please load the digital coupon to my card. He told me that he could not do that and the only way I could get the discount was to download the appt. to my phone. I told him that I only have a flip phone and could not do that and asked if he could please load it to my card. He said no and he could not and would not give me the discount. All other grocery stores will do that for their customers. I am 70 years old and not very good with using the phone for these things and find no reason that this store would not accommodate me for the purchase. I put the ice cream on his counter and walked out of the store.