I had the same complaint about smurf issue in ranks above 15 weeks before and someone told me they technically aren't doing anything punishable despite being complete assholes and I have to agree on that, community manager also disagreed on punishing smurfers so yeah, the only solution to get rid of smurfers is to farm everything in campaign to improve your mech and you won't see any smurfers after a certain point.
In my experience I have never seen a single hacker or cheater above r15, so there might be something wrong about your statement, but apparently there's actually few cheaters somewhere in r10-r5 and I hope Gato will do something about it