Yep , I have had items cancelled on an order... it really chaps my ... when that happens. The one that I found did it more than once to me ... has not recieved an order since. No call to see if I wanted to substitute... no "gee we did not have the inventory we thought" ... nothing ... A bad way to have a transaction close .. with the buyer dissappointed.
I was always taught that in the general rules of retail it takes more $$$ to get a new customer than to keep existing one happy.