FREEPORT, N.Y.—Wayne Wahrsager, president of New York Merchants Protective Co., Inc. (NYMP)—a full-service alarm company here that’s been in his family for more than 100 years—contends the company’s court-appointed receiver is grossly mismanaging the business, causing “staggering waste and losses,” and also trying to fire the person vitally needed to ensure the business survives: Wayne Wahrsager.