On 2003-04-09 I sent a
Linksys Network PC Card (WPC11) to
Linksys for repair.
(It had fried when "Windows Update" found an update for it
and I (perhaps foolishly) said "go ahead, install it ... make my day!")
I easily found their RMA page
and generated an RMA (Return Merchandise Authorization) for it.
I didn't include a receipt, since I couldn't find it.
Nonetheless, they speedily replaced it with a working card, at no cost.