You contact Steeven or Mattches. This is kind of addressed in the FAQ at -Retired- PSA: User FAQ - Support & Answers. check it under How do I know if I've been flagged?
What action? Btw, I’ll also say that while a lot of people are having similar consequences, not all of them are from the same reasons. Don’t forget that while there are many who unknowingly had things happen, there are lots who are regularly trying to deceive others for profit. So just because people might be flagged or have the same outcome as you’re experiencing, it matters greatly as to what led to it and how they react.