Nightmare Order

I had a shopping order at Dollar General (I know, I know, first mistake). it was ordered on the DG app, so it was just grab the items, scan the code, scan the items, and leave. however, two items were out of stock so I had to substitute. and at checkout, it didn't accept them. contact support, and they say to just cancel. but it won't let me (or the customer) cancel. so I finally get them to unassign me without affecting my completion rate. but that meant I spent 30+ minutes on this order for nothing. and it caused issues foe the customer.