highly disappointed with ecovia service

1. Ecovia provide the car with half fuel tank, but did not mention it in a document. I was not able to identify this on pick up, since the dash board has 2 fuel meters: CNG and Gas, I was lookin on the Gas, not being aware of the 2d. I've sent an email, requesting to confirm this done by intention, few days later to both central and pick-up (Bergamo airport) office, but got no reply. Have remind them 2 time more, got no reply. They eventually replied right after my car was returned, but did not relate to my question at all. Finally, I requested to refund me for half tank, as I returned the car, but there was no refund. 2. Ecovia provide me with a car with CNG fule, which was highly uncomfortable to find a fule station for it. On counter they said they have only this kind of car.