Banned from clubs, rivals, and auction house

Was recently banned from the auction house which I’m upset about because I have about $1.3 million in their that I bet on a car with that I can’t get to now. In saying that, I was given no prior warning to this ban and the link it gave me to figure out more information was pointless because it offered no help. I even contacted Xbox support and they told me they couldn’t help me either. If someone could just simply tell me the reason I was banned It would be great.