Unfair treatment

They towed my vehicle to one of Dialdirect's authorized tow company's yard and the day after they told me that my vehicle has no cover and I asked for the vehicle to be returned, so they promised me the vehicle will be returned. But eversince then I have no response from Dialdirect and the owner of the tow company does not want to release my vehicle even tho I have a written email frol Dialdirect stating that he must release my vehicle.