Beyond the claim on the front page, I can't find any evidence for Arduino support.
As the man said, a strongly-worded letter is in order.
Hi there, no need to send any emails.

ROBOTC for Arduino is still in its Testing stages for ROBOTC so it's not currently being sold for any price. The Arduino version of ROBOTC is currently being used for our Multi-Robot communications research. So yes, ROBOTC does currently work for the Arduino, however, it's still in its testing and research phase. Now that the beginning of the competition season for the other platforms has passed, we're hoping to put more development time into pushing out a final release.