I was wondering how you would handle customers returning items bought with bitcoin.
Will you send them back the bitcoin or give them the equivalent in fiat currency ?

Isn't there room for abusing this ?
Someone could buy something in your store for 100$ worth of bitcoin. Now Bitcoin prices drop and he asks for a refund for 100$. Now he can just buy back more bitcoin essentially. If the price of bitcoin rises however, he could ask for the bitcoins back and buy the items with fiat currency and sell the profit in bitcoin he made.