First I understand that when it's busy have to go over and make do with what you can.
However, that should not excuse messing up an order.
After confirming that the order was incorrect I handed the sandwich back to the Jimmy John's and inform them we ate what was missing.
Instead of resolving the issue, they handed the sandwich back to me and a packet of mayonnaise to resolve the issue.
The only way I'm going back there is if Subway and Jersey Mike's are closed.