How long has this been going on? So they are charging more than PStars and about triple what they say they charge? Now you may be on to something.
How about more people checking up on the rake charge and posting the hands as you did.
The earliest hand I've seen that was over charged was November 14th.
The earliest Betcoin was made aware of it was November 15th or 16th.
Since then multiple players have brought it to their attention.
Some comments from other players on Betcoin Forum:
You're right.2 weeks 3 days ago
I just checked myself and you're right, the rake is definitely wrong...they are raking way more than what the chart indicates.
Wooooooah...2 weeks 3 days ago
is 100% right, just observed a 4/8 HU game where it was raked like 4+.
This chart is definitely NOT accurate regarding what is actually being raked! I'm sure Betcoin isn't doing it intentionally, but this needs to be fixed ASAP.
It's definitely still not right.
This screen shot is from just now.
5+ handed at .5/1 NLHE table
Should be taking 2.5% with a 2 chip cap

I also saw them taking 3 chips from a 3 handed 3/6 NLHE game (should be 1 chip cap) and 3 chips from a 3 handed .5/1 PLO game (should be 1 chip cap)