Why sometimes a buyer has infinite revisions?

[zenter]

Hi, I am currently struggling with an order since the buyer keeps asking for revisions even when the max amount of revisions is 6. They keep asking for revisions just a moment after I deliver. Always with minimum changes instead of making a list with the changes they want so I can make all of them and deliver a final version they keep asking for a revision. I have already delivered 8 times and the max amount of revisions of that package is 6. What is happening? They didn't pay for extra revisions either. 

Edit: I already told the buyer like 3 revisions ago to make the list of changes and they just didn't answer to that. 

[enunciator]

It seems you are being taken for a ride by an incredibly nitpicky buyer or an outright scammer who is intentionally trying to drive you to the point of cancelling the order and run away with whatever work you've already done for them...

IMO, 6 revisions is waaay too much and you should have put your foot down and be firm after the final official revision that any additional requests would require additional payment. But since you kowtowed by offering 2 additional revisions free of charge, the precedent of being viewed as a pushover has already been established.