What can I do to clear up a parking ticket for a car I no longer own

Parking violation on a vehicle I no longer own.: I was issue a parking ticket for a car I no longer own. After many attempts to prove to them that I no longer own the vehicle, including a copy of the release of liability from the D.M.V. the city of Los Angeles has sent me to collection saying that I didn't prove that I did not own the vehicle in the proper amount of time. At the time of the ticket they said they received from the D.M.V. my name as the registered owner, I went to the D.M.V. and they told me that was not the case. What are my options? - Is this your question? Add additional information