The first reMarkable I purchased ended up getting a row of dead pixels. I contacted support with some images (December 16th, 2019). They sent me to the support page for returns and I just followed the instructions (within a day or two).
It basically looks like the polarity of the e-ink reversed itself. When the background is white, that one row wants to be black. When the background is black, that one row wants to be white.
I scheduled pickup with the courier on Christmas Eve (December 24th, 2019). Roughly two weeks later I got the new reMarkable back.
Provided shipping label and waybills. Courier came to me; no need to walk or travel to drop off the package.
Throughout the process of the shipping and review I received notices of where the device was in the process.
I wish I didn't have to print the labels at all (I understand why) because I don't actually own a printer and haven't for over a decade now.