From what I've seen, by the time questions escalate to complaints the player is leaving regardless of how things get addressed. So why bother? If a coach isn't willing to answer questions then that is a red flag, but if a parent is popping up out of the blue with complaints it is on them, and the team is better off without them and their kid. If it is within the first month then that family either joined without asking the appropriate questions, or in bad faith under the delusion that the rules don't apply to their kid.