I think net metering is a delivery thing which Eversource or UI handle by default. The others are strictly supply.
If you own the system, depending on its tier rating, it could/ should be covered by the OEM. Lower end systems do not have long or reliable warranties however. Do you know if the installing company was bought out or did they just go out of business? If they were acquired then the new company would have to assume those liabilities unless said liabilities were discharged in bankruptcy court.