I just returned a computer that I purchased online for which I paid with Visa. When I took it to the store, no questions asked about why I was returning, but they could not credit back to my visa. I had the choice of cash or gift card. I took the cash. So, from now on, whenever I buy something online, I will pay with my Amex.
The onliine store for some reason takes all c/c's, but they told me the physical stores are different.