It's a perpetual battle then because if you don't ignore, they get the drive to shit post much more and create more account but if you do the opposite, they will come to a certain point where they will get tired because people don't get worked up over their stunts and might get disheartened in the long run.
I think you're confusing trolls with users that are trying to bump up their threads for visibility. Trolls feed on the reaction of users, but those that are bumping their thread mainly do it to get their service or goods some attention. Ignoring the excessive bumping means that they just get to continue doing it, and getting their product/service out there, without any repercussions. Excessive bumping, and continuously ignorance towards the rules will likely get them banned. However, for first time offenders, and one offs its usually just deleted, and maybe the moderator will send a message to the offender.
although people who are banned will get banned again when they use another account on this forum and are discovered, but for those spam elements that way, people usually ignore it rather than care too much like you