They say it's around 10+ returns per week for a short period. Maybe like doing this for a month.
I doubt it is as easy as 10 returns a week and you're banned. If it was, Best Buy could had implemented this without needing to pay for TRE's returns tracking system.
I'm not banned or flagged at around 3 returns per week. Sometimes, I like to drive to other BBs to return because that Geek Squad guy is remembering me...
As for how the hell do I do 3 returns per week, I spend a lot there thanks to CAG. And with Silver, the points and stuff keep racking up. I currently have a $20 cert waiting for me. With a lot of impulse buys, some stuff goes back.