No, you can't compel them to honor the layoff (you can ask, of course; but you can't make them do this). The employer, not the employee, has free right to change an employee's job duties, department, coworkers, etc., and also whether to lay someone off or not. Your employer has the right to decide to transfer you to a different department instead of laying you off, and since it is their choice, not yours, you can't compel them to honor the lay off.