I paid in bitcoin, now I'm owed a refund. Can I demand it in bitcoin too?
I am not a lawyer, but...

The Coinage Act of 1965, Section 31 U.S.C. 5103, entitled "Legal tender," states: "United States coins and currency... are legal tender for all debts, public charges, taxes, and dues."

In the USA all monetary debts can be paid in US dollars.

Second, while bitcoin is legally a payment method in the US, it does not have legal status as a currency. In the eyes of the law it's almost certain that the company will only be required to send you the original USD price of the item that you paid, regardless of the method of transfer. Legally speaking, you paid dollars through bitcoin, and the firm will return your USD, using the bitcoin payment method if you so wish. They also won't have to refund any expenses you incurred to get the money to them, like driving money, bid/ask spread you paid to buy BTC, PayPal fees, etc. 

Btw, the original price was listed in US dollars, right? Not BTC. 

I'd love to hear a small claims judge berate you for trying to, how can we say this, 
enjoy risk-free speculative gains through the abuse of company refund policies.

Indeed if this unethical method worked, I could always use BTC to buy something with a money back guarantee, and if BTC went up a lot, just ask for my BTC back and cash in! If BTC didn't rise, I'd just keep the goods I'd originally bought, or maybe ask for my refund in US dollars, Swiss francs, gold bullion, IMF special drawing rights, or maybe even hugs...