A discount code was app**** to my cart and was visible on my profile

A discount code was app**** to my cart and was visible on my profile. When I processed the payment it failed on my debit card so I updated payment and it went through at the full amount. No where did the app communicate that the code was no longer app****. I tried contacting their support, where i got a generic response from several service agents. This was the first time we decided to use UnerEats as they are new to our area Because of the deceit i will never ever use UberEats again and really disappointed with the level of support received