Dont Ever Load This App

Used the app to check in ahead of time. The app asked if we would like to updgrade to Comfort Plus for additional $49. I say "yes" for six passengers. The app allows me to select my new seats. Confirm and pay, all good UNTIL I get to the airport. The seats I selected were not Comfort Plus (why would the app allow me to select these?). Ugly scene at the ticket counter as no one there knows the app. I will continue to work with Becky in India on my upgrades, etc.

Humiliated at Haneda about Fly Delta, v4.0.1