That said, you should be able to get a refund from BFL in USD.
Huh??
He mean they will convert the USD value of the product you bought to BTC based on current exchange rate if you want to request BTC refund
Unless the exchange rate has fallen since then.

Then I bet they only return how many Bitcoin he paid.
Clueless. BFL takes BTC payments through Bitpay which means whatever coins are immediately converted to USD and sent to them. BFL does not have a storage wallet they keep BTC in, they only have the USD. If you had bought in May when BTC was $100-120 and refunded in Aug when BTC hit $70 you'd have done well.