Nowhere to apply code before checkout MC 50

I just signed up for a 1 year internet plan with Xfinity. While I was checking out, I was given the code MC50 to apply at checkout. There was nowhere to enter that code! It says I should have received a $50 gift card if I signed up same day, and that's the only reason why I did. Did this get added to my order automatically? Can this be added to my order if not?

I can't find a way to talk to a real person.. thank you in advance for your help.