So, according to what you said the Mayor allowed you to KOS people which is not allowed at all. If you read the Mayor Job rules in the Server Rules forum you can see that it says
You may allow certain players permission to enter PD and spend time with you past the 2nd door, but they may not enforce your KOS rules.
The mayor CANNOT enforce KOS rules to other players no matter what circumstance, also the Mayor cannot put a law for "KOS Is Legal"
No minge laws. (this includes KOS laws, J-Walking laws, and any law that would restrict a player's movement)
You did kill more than two people according to logs, therefore it is identified as "Mass RDM" and is bannable for 2 Weeks. The person you reported did get banned for RDM + LTAP but that doesn't mean you can go around and KOS people because the Mayor told you to. Provided in the screenshot with "TCG Pepe but call me Peep" you can also see that he Mass RDM'd as well. I STRONGLY recommend you refresh yourself with the server and job rules, I'm sorry you feel this way about me and I hope you have a good rest of your day!