If someone sends $50 worth of Bitcoin, the refund should not be $50 worth of Bitcoin.
The thing is that they are a fiat company - so when they received the bitcoin they changed it into dollars immediately. The price then moved, and they refunded you in what were to them dollars. They would do the same if you paid them in say euros, they'd change it immediately to dollars, and then refund you the dollar amount of euros.
Part of the problem here is that bitIcoin's price is swinging too violently to be useful as a currency. Currencies need to be steady, moving only 1 or 2 percent a day, not wildly swinging by 20% at a time.
Well, that could be. But that's an unsafe practice if they plan on doing a lot of business with crypto. They should only cash out when they confirm a completed sale, in my opinion.