I'm confused. Where is the part where he scammed you? You were only entitled a $120 for a week and as far as I can see you have only done 1 week of "work". He agreed to pay you that and yet you ramble here with your butthurt because you can't get what you want. He's the one managing the campaign and he has the rights to deny anyone.
As for that $840 you keep mentioning, it's not like it will go into his pocket. He will use it to pay that someone else who he hired as a replacement.
Just take the money shut up and move on with your life.

This argument of yours will go nowhere.