OP, I understand your frustration. I think a very diplomatic and calm approach, with the head manager, would be the best way to go about getting some sort of compensation.
The "con" goes like this:
Complement them for taking the time to hear you. Use their name and look them in the eyes. Acknowledge they have the power.
Now the tricky part. Guide them to the conclusion that helping you is actually easier than not helping you. This works.
Also, have realistic expectations of what you will get. They are not going to give a pile of cash. Maybe a free car wash, IDK. It doesn't hurt to ask. And, if things go well, you might be pleasantly surprised what they offer.
My dad always said: "The squeaky wheel gets the grease!"
Good luck!