The diner has an issue with the order. What can I do? Abigail Marchione Updated December 07, 2018 15:42 Follow Advise the diner to call into Grubhub Customer Care at 877-585-1085. Customer Care will help them sort out the issue. After letting the diner know to contact Customer Care, move onto the next delivery. Related articles Someone else picked up my order at the restaurant. What can I do? I need to reassign an order I’ve accepted. What can I do? I’ve accepted an order that is already late. What can I do? What should I bring with me on deliveries? Where should I start my block? Comments 0 comments Article is closed for comments.