I did that. There were no options, just a dialogue saying they had refunded me a couple dollars for a price mismatch. But no button to report an issue on the app or web, no chat, no email or phone number. Just a Contact Us form that I filled out and submitted with all the information nearly a month ago, and no one from GrubHub has reached out. I finally just did a chargeback a couple days ago.
It’s a hell of a lot easier to disable than it is to enable, especially if you’re not disabled. It’s a minor inconvenience once for us, but enabling it could be exceedingly difficult to overcome for someone else.