Maharashtra Natural Gas [Mngl] — Customer care phone does not respond

I have tried calling the customer care number of mngl pune and the 1800... Number but even if the ring goes it drops off within seconds. Further it seems there is no automatic acknowledgement of the mails as i wrote to them about erroneous bills and undue penalties they keep adding in my bill. Very unprofessional. Govt should not allow any monopolies otherwise this is the kind of treatment a consumer gets. I think my hp cylinder agency was better for a few rupees more, but reliable and responsive