What you do here is tell your credit card company that the charges are fraudulent and that you have informed Lyft that the card is not authorized, but they refuse to do anything about it. Let them handle it - they will.
The guy's e-mailed Lyft support and hasn't got an answer.
What downside is there to reporting the fraudulent charges for what they are, apart from a tiny possibility of being banned from using Lyft in the future?