Game's manager, Wack 100, tells TMZ ... Simmons' claim he arranged a peace treaty between Meek Mill and Game ... is full BS. Wack says Simmons "must have discussed this in yoga classes with Meek," but he has no right to discuss Game's business.
He says Russell did briefly speak to Game, but the rapper basically told the mogul to butt out ... in more colorful language, we're guessing.
Check out the vid we got with Simmons Thursday morning in NYC -- he told us the beef was not only squashed, but he hoped there was a chance Meek and Game would work together in the future.
Game obviously disagrees. Strongly.