So merchants are actually taking a huge risk by using Bitpay?

Let's say you get hit with massive sales during a crash...I'm assuming bitpay will not allow you to just refund the original BTC amount, (seeing as the dollar exchange has already been done), so you are screwed with whatever you get?

In general how do refunds with Bitpay work anyway?  Seeing as you can't refund the person the same amount of BTC that they paid because the price will have changed?

Also note that given the volatility in Bitcoin pricing, if you require a refund it will be in normal human currency, like USD or CAD