It is difficult to get unbanned. However, some seem to have been unbanned because they were extremely lucky and found the most generous person at Niantic to consider their case. Others convinced someone at Niantic that they would never use third party software again. Most of those that were unbanned were not actually using bots but were using third party maps. Someone at Niantic may have been confused about this if all of my friends that claim to have been unbanned were actually unbanned. I had 10 different accounts banned, and I have not had any of them unbanned.