A client doesn't reply to my messages and doesn't pay for a work i provided as a paid sample (10$). Unfortunately there is no contract to that since i thought it is only a sample and I will just send it straight away.
Can i report this?
Can you report this?
There is nothing to report.
Clients are not obligated to respond to freelancers.
As a freelancer, I get paid AUTOMATICALLY if a client does not respond or do anything.
If you do not get paid for this work because the client doesn't respond, then it is because you used the Upwork tool incorrectly.
Rather than worrying about reporting the client, you should work on figuring out what you did wrong.
If you worked without having a contract in place, then that was your mistake. Don't do that again.