Poor customer service

I placed an order with this seller for 2 items. The seller went a week without any communications, before sending me an email to tell me they were out of stock on the items and they were canceling my order. It just so happens that this ridiculous delay has caused a major inconvenience. I was depending on these items to be here by now, and I not only am out of the items, but am out of time to order them elsewhere. The seller should have contacted me long ago to notify me that 1) they were out of stock and 2) giving me an option of waiting for the items to be in stock, or to cancel my order. 1 week is far too long to contact me considering Amazon requires sellers to ship items within 2 business days. I should have had notification by 5 days ago, at the very latest. Extremely disappointed.