Cheated on wins

I was in 2nd place on the Arena challenge that just ended.  I stopped playing when there was 30mins left in the challenge and was 80 points ahead of the person in 3rd place.  It was impossible for the 3rd place person to pass me in the time (80 points / 5pts per win = needs to win 16 games  -  16 games x 3mins per game = 48 mins)  When I opened the app a few hours later, the Arena Challenge ended with me in 3rd place instead of 2nd.  Rigged