If you put in an order last night or early this morning and your vendor cancelled and told you to reorder, it's time to get a new vendor. They're fucking you by rejecting bitcoin when prices drop so they're not losing any money (you are; you're going to have to buy more bitcoin to purchase their product). You can bet your ass that whenever bitcoin had gone up when you purchased, they're not refunding you the difference, and this is despicable and shady behavior. Stay away from those vendors in the future!
Start a list right here. That is like price gouging people escaping a flood during a natural disaster. I bet none of them canceled shit when the coins were climbing to the moon last week.