Stop downloading stuff from Youtube. Free "hacks" or "bypassers" aren't legit. Your key wasn't banned, it was swapped for a banned one. Buy a legit key and forget about hacking, all it's going to do is cost you more money than the $20 you'd spend on a legit key.
You could try to reporting to battleye that your key was stolen, though I've heard their customer service is not the best. You could always buy a new one off Steam or buy one from the market place.
Solved.
/Closed