I'm going through the refund process with Kobo myself. I debated on whether to wait for the replacement Aura One or just refund it and buy another one. I decided it would be faster to just refund it since I only have 30 calendar days to do so according to the term of sales.
However it's been a week and I've yet to hear anything back from Kobo except "Please allow us 24-48 business hours to provide you with an update on your request" every time I ask what's going on.
I have a little over two weeks left to hit the 30 days from purchase mark and I brought the issue up with Kobo the day after I opened the box.
I agree that US customers get screwed over and the call center that Kobo outsourced to seems to agree. The person helping me basically stated that if I had purchased it at a store it would have been a lot better for me. I would have loved to have bought it at a store, I searched high and low for an Independent Bookstore near me that might carry them, but no one seemed to know what they were so I had to buy it directly from Kobo. Buying directly is fine when there's no problems with the reader but I'm starting to dislike their customer service.