How do I report a user?

[rpb21]

I sold an item, but the purchaser didn't pay. I opened an upaid item case and they never responded, so I closed the case to get my fees back. However, I looked up the buyer and while they have been inactive for a year, a year ago, they were doing the same thing. They didn't pay for items or paid and then opened a dispute. This user needs to be removed, or atleast tagged by ebay for abusing their rights as a buyer. How do I at least make Ebay aware of this, because apparently there's no punishment for people like this.