Offering up your complaint as a suggestion will almost automatically make the receiver of the complaint an ally.
Never chastise, berate, curse or otherwise mistreat who you are complaining to; 99% of the time it’s not their fault and would really like to fix the problem. Cursing them out in front of everybody more than likely will not get you what you want. It’s always better to pull them to the side and let them know privately what the issue is.
Always be clear, direct, and say thank you for listening.
Let them know you’re reporting the complaint because you know they can be part of fixing the problem.