I work for an online retailer. I had a phone call from a customer that had ordered from our website that went like this...
Angry Customer - "You've not sent me everything I've ordered!"
Me - "Okay I'm sorry about that what appears to be missing?"
AC - "Item 2 is not there. You've only sent me item 1. This is ridiculous. Every time I order from you it's a nightmare and this time it's for my sons birthday. You've ruined his birthday!" - At this point I checked the customers history and could find no evidence they had ordered with us before.
Me - "Okay I'm really sorry about this we'll get this sorted out for you as quickly as possible. Have you checked inside the box of item 1 to see if item 2 has been put in with it. I know sometimes we put item 2 in the box with item 1 to make sure it doesn't get damaged." - Item 2 was much smaller than item 1.
AC - "I haven't opened the package yet I'm still at work."
Me - "You haven't opened the parcel at all?"
AC - "No like I said I'm at work I haven't had time yet."
Me - "Okay can you please open the package and check to see if both items are inside and let me know?"
AC - "I'll have to call you back later I'm at work."
And we never heard from the customer again.