Dispute result came out in my favor and same buyer purchased again.

I have had one dispute with one of my buyers. I submitted a dispute and the result came out in my favor and I received invoiced payment. Right after the result posted on our workstream, the same buyer purchased another hourly but yet he did not submitted requirement to get this job started. I have some real concerns over this. I should have had the option to block this buyer from purchasing my services. How can i work on new project when i had very bad experience? Even if i complete new task he can leave me bad comment and rating. Or if can complaint this one i have to pay dispute fee and what is the grantee that he will not purchase again?

Please guide...

Many thanks