You placed an order and accepted the price shown on their website when you
placed the order, they charged you that price, and they shipped the goods.
The fact that the price dropped a couple of days after you received the
order is just bad luck. They're under no legal obligation to refund the
difference. Regardless of how it was handled by them, you've got a fair
amount of nerve to be posting not to buy from a company simply because they
won't agree to an unreasonable demand that you're making.