He spawned with pike on horseback 2 rounds in a row and was reported by a guy in our TS about it. He also made a message in game about it.
Not only this, but you waited to spawn when no one was around so that less people would notice you exploiting, making it pretty obvious that you were trying to hide it.
Regardless, there's no point to argue here. It's a pike, it says "CANNOT BE USED ON HORSE BACK" when you buy it and when you select it on the equipment screen.
It's only a 3 hour ban because pikes on horseback is a zero tolerance rule for me, so don't feel bad.