Installation previously done by solar city with out permits as well as main 400 amp panel upgrade.Yes not to professional;Now I am involved with city permits as well as re connection of solar system.All is good with main distribution.Upon connection of solar lines i simply replaced the wires on same phases as in old 400 amp service load side of meter.prior i had shut down all disconnects as well as main feeders.Once re placed on load side of meter all seemed well .now i have received call from customer they have not received credit on their bill. yet they are under construction.the old 400 amp meter had drilled lugs between meter and main am i missing something he this seems pretty self evident .Is it possible the meter went bad they are in an area with many brown outs .