The Overwatch system is utterly terrible and their conclusions are often inaccurate. I'd say there are 97% probabilities of you being banned for not cheating and hitting legit scout headshots through walls and smoke, and that's some next-level senselessness.
People spend their valuable time on DM servers in order to advance their skills, and hey it works flawlessly for people like me, we learn and spam shots in obvious spots now and then.. Sometimes it works and sometimes it doesn't... Same goes for the 64 tick MM servers. However, hitting a couple of scout headshots through walls and smoke doesn't make you a cheater, and receiving an overwatch ban for it, is some next-level foolishness. It happened with certain someone I know personally. There are plenty of cheaters roaming in this absurd game, but they never get caught (seen plenty, saying with years of experience) but they cross a line when they ban legit people.
There's no proper way to contact the valve, and it's not like they would ever answer. It's their tact to make money after all.
Their MM system is worse, and the valve should take necessary measures as soon as possible, if they don't then with all my honesty I don't see this game gaining numbers of mature community players (Like it has 'em currently lol). What'd happen when DMG + player gets matched up against silvers or novas? The answer is quite simple, Gold novas will get demolished. But, that doesn't make the DMG player a cheater... And ultimate stupidy is to send their demos to NOVAS for a conclusion.