Well, I don't think Polearm Gamble isn't broken or overpowered. It's very good (for a fighter) keeping melee opponents from getting past him, given a choke point - something fighters are already good at. The glaive does poor damage and has average accuracy (2d4, +2 hit), although as a heavy blade it qualifies for various OA feats which work well in conjunction with Polearm Gamble. It's a neat build. With enough feats, the fighter can make OAs with +WIS +2 (Heavy Blade Opportunity feat) to hit against anyone that moves adjacent, stopping their movement, and can use an at-will attack in the process. Uncanny Dodge negates the +2 to hit that the now-adjacent enemies would get against the fighter (from CA).
However, the fighter has no shield and is constantly granting CA to melee opponents. If he's been pumping up his WIS to enhance his OAs, then his Reflex defense is going to be especially poor. The answer is the same answer you have for nearly any fighter - hit him from range or go around. "Go around" is still very possible - Polearm Gamble does
not give threatening reach. For example, where "M" is a monster and "F" is the glaive-wielding fighter:
Code:
-M---
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--F--
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the monster can move past the fighter without getting hit at all (by always staying at a range of 2 squares). Polearm Gamble only triggers when an opponent moves next to the fighter.
If the fighter is using the Battlerage Vigor build from Martial Power - that might be the source of the DM's problems, not Polearm Gamble.