Members posting too much

[setishock]

They'll get over it in time but that doesn't help you now. Keep the PM's you sent them and send another being a little more stern.
It sounds like maybe they want to pump up their post counts or if you have a reward/promotion system in place they might be working to artifically pump up their post count to get to the next level.
I would check IP's to be sure it's not the same person.
And like rootsxrocks said if you get tired of them point them to my place. They can wear it out all they want.