I have one of these, I think (will have to check the nameplate). It was given to me. How would a refund work here? Is there some standard sum involved, or do I need evidence of what was paid for the unit originally? I don't have this.
In my case, I had to take a picture that showed all of my name (on a piece of paper), the model number on the back, and the power cord having been cut. I submitted this and maybe a month later I got a check in the mail. I didn't buy the unit; it was already in my house when I moved in.