Here is a letter I wrote to a yarn company that only sent me 83.33333etc% of what I paid for (and ordered).

Dear Lovely Yarn Artists,
I am writing a message of dual purpose. First, thank you for my lovely, gorgeous, smooshy yarn. I love it. My fingers are twitching, my needles are full, and I am already drooling over future purchases.
My second purpose in writing is slightly less positive, I’m afraid. You see, I ordered six skeins of Eidos from you. I ordered six because I’m planning on knitting three stranded projects this Fall, including the Hwaet! pattern I bought from your website. But my package arrived and (sob!) there were only five skeins, leaving my husband’s second Hwaet! skein MIA. Incidentally, the excuse of knitting my husband the fabulously literary and rather extremely obscure Hwaet! socks instigated and justified the entire purchase. I’m sure you know how that goes…
Alas, the Lithos colorway appears to be out of stock. Or that is my inference, given the penned slash through the “1 | Lithos” line of my invoice. I understand how this kind of thing happens, and I am sure you must also understand how one often buys a second colorway because of how it would look with another. The weird thing is that I WAS CHARGED for the skein that I didn’t get. At least, that’s what I surmise from the “This Completes Your Order!” email you sent me upon shipping, in conjunction with the fact that I paid for 6 skeins. Had I been informed that the Lithos colorway was out of stock I would have been much less surprised and disappointed that my package contained only five skeins. I might have even had the foresight and opportunity to find a substitute! Alas, indeed.
Considering the fact that I wasn’t informed of the backorder or asked if I wanted to select a replacement, do you think I could choose a replacement and have it shipped without being charged for shipping? Even better, do you think it will be long before the Lithos colorway will be back, large and in charge? And am I first in line to receive it’s neutral goodness then (without paying for shipping)?
Respectfully, and with much gratitude for your consideration, I remain your knittish fan,
Stephanie Goodrich
(a large glass of wine *may* have contributed *somewhat* to the tone of this letter… maybe. smooches!)