Tell them you're willing to stay and continue to pay the same or go elsewhere if they insist on more. Same money or no money - their choice. Bet they buckle.
Of course, this means risking your membership to a place that's been trading on a relevancy it had 35-40 years ago, so you'll have to decide how hard you're willing to take it up the shitter for the privilege of saying you lift at Golds.