Vadim, I am not certain what hints I could offer other than what you have already tried.
I can't give any reliable information about how BookBaby has been for me because so far I've only been with them about three months, which means I've only see results for the first month ... and there wasn't a lot to see
. But the few Amazon sales certainly showed up (I don't go direct to Amazon, but can see the sales summary on authorcentral).
I do know that it all takes much longer to happen that it really should, but I'm not certain how much of that is BookBaby's fault. It is disturbing to hear that they appeared to ignore your cancellation emails. If I've had a complaint about BookBaby in my short time with them it's how slow they are to respond to emails (generally a week), but so far they have actually responded to my few queries (I just wouldn't like to be holding my breath waiting).
I would be interested to hear how you get on, and whether BookBaby eventually get their act together and sort out the problem for you.