Subway

I ordered through Tap2Eat and showed up to collect my sandwich at the designated time. They were 5 minutes behind schedule so I was able to watch my sandwich being made. Employees missed a topping I had asked for in the app and I pointed this out to them as they made it. They just said that they had already put it on, but when I insisted they said it was too late to change. The sandwich wasn't wrapped up, it was open right in front of them. How hard could it be to check the order and then check the sandwich to see if an indicated topping was missing? The topping was indeed missing and I was unable to fully enjoy my sandwich.