Yeah, I returned it and should be getting a refund soon.
Bricking the player was almost for sure caused by the RockBox you tried on it. My experience with RockBox is very, very bad. I bricked my HM-801, and only managed to get it back by doing a more than "interesting" hardware trick. The stock firmware leaves much to be desired in terms of gapless playback, EQ and cover art, but does the job. And of course internal memory is accessible.