Banned on coliseum

A day ago, I participated in the Coliseum mode and played twice. After the first time, I decided to play a second time to improve my results, and during the second attempt, a 'Coliseum Cheating' message popped up, and I was kicked out of the game. I don't know what to do about this. After looking into it, I saw that I am not the only one with this problem.

My Ally code: 669-818-187 (669818187)