re: "what do i do if my client scams me"
If your client scams you, it means that you made a mistake.
You either violated Upwork rules, or made a tactical mistake, or both.
What do you do?
You describe the situation here in the Community Forum, and you ask what you did wrong.
People in the Forum will explain the situation to you.
You learn from your mistake, and then you don't make that same mistake again in the future.