Given that you've deleted the thread, the scammer can easily create another one or lets say you ban them, they will return no matter what.
IMO the dedication of these money-grabbers are the very reason why Bitcointalk decided to not moderate scams.
It might also be the reason why they came up with a trust system.
There is another solution to stop scammers or at least slow them down, better than the trust system, but the staff refuse to implement it. very sketchy imo.
https://bitcointalksearch.org/topic/scam-preventionremove-self-moderation-for-topics-within-the-marketplace-2929216
People will continue to be scammed whilst the site provides scammers with scamming tools.