This has happened to me more than once, and it's very frustrating.

I go to a site to order something specific. I do, and while I'm there I make a couple of impulse purchases of small items, just because. I send my order, then get an email notice back in a few hours saying my credit card has been charged, my order has been shipped, but by the way, one of the items wasn't in stock. Guess which one? Yep, the one I went there to buy in the first place. Because it wasn't in the order, the shipping costs for the two or three cheap items I added onto the order are more than the costs of the items!

Now, I NEVER would have bought these items under those conditions. Not only won't I get the item I wanted most, I end up paying through the NOSE for those smaller items. So I'm torqued when I get the email, I'm torqued when I get the credit card bill, I'm torqued when the items arrive, and for years on end I'm torqued whenever I look at them and think about how much I paid for them when I didn't even want them that much in the first place! Grrrr...

I wish when you place an order online you could indicate 'this is an item I really want' and 'this is an impulse buy' and 'cancel my order if you can't ship the item I really want'.

Some dealers have an instruction box on their checkout page. That's where to do this.

I really prefer to phone orders in, anyway.