Data point - bought some stuff from tiger direct and when I tried to cancel (before order was shipped) was told I had to get item, then return. They gave me return slip, but no shipping slip, and never responded directly to my requests for one (i.e., "Can you please send me a shipping label?" Them: "you have a return slip").
Finally disputed with AMEX, they decided against me, since I still had the merchandise.
I printed out the entire email thread, showing that I had tried to return the merchandise, they "reviewed" and decided against me, because...I still had the merchandise. When I called and spoke to a supervisor and pointed out that the documents I had submitted were to address that precise point, he agreed, said he didn't understand why they hadn't seen that, and refunded the charges on the spot, told me to keep the stuff.