I'm pretty sure I wasn't even mean when filling out the Amazon.com support form indicating that the device they sent me was not as advertised.  But this has got to be one of the most apologetic emails of all time.

"""
I'm so sorry about the problem you had with your "[...awesome wifi interference generator...]." 

I realize that this has caused utter disappointment on your part. To say that this is an inconvenience would be a complete understatement. 

At this point, I need to look into the problem and I'm going to create a ticket for this to confirm from our suppliers and from our Fulfillment specialists if the item is really [technical detail thing]. 

I just wanted to let you know I'll write back in 1-2 business days with more information. 

I realize that at this point of time, this would be disappointing, but in a situation like this, it is very important for us that we provide you with accurate and expedient resolution and I find that this is the best way to be certain that your issue is resolved more appropriately. 

Hoping for your continued patience and understanding and thanks for giving me time to find the best solution.
"""