Mohammad Sazzad H.,
When this happens, make sure the client clearly states in writing on the Upwork message board exactly what he wants you to do and get him to confirm in writing that (s)he is expecting you to do some work without payment. Be subtle about it, so the client doesn't realize you're setting him up.
You can then complain to Upwork that the client has asked for free work and they can easily confirm the client's TOS-violating request.
Whether or not they will actually remove such a dishonest client's bogus "feedback" from your JSS calculation, no one other than an Upwork employee can tell you for sure.
But I would hope so.
