It’s not so much that a person would “refuse to be subpoenaed” as they would “refuse to [honor, abide, comply with] a subpoena.”
You can do this formally, by filing a motion to quash the subpoena in the court where the case is pending. Generally, though, the mere filing of a motion doesn’t waive your obligation to show up, but if a court order is entered protecting you from the subpoena before the date you were supposed to show up, you don’t need to appear.
Or you can do it informally, by just not showing up. Doing that risks the court issuing an order compelling you to comply, and violating a court order risks contempt of court.