There's an e-mail address also for GM feedback. You'll never hear a result, but it doesn't hurt to submit feedback to the GM's supervisor. The GM is apparently ignorant of his employer's policy and personally biased. I'd report him.

Just on a note: I complained about the GM's on the CS forum once, since then, I've never received an answer to any question I've posted there from the GM staff where before they were helpful, so idk, GM's can be vindicitve pricks imo.