Bhagyanagar Gas Limited - Bhagyanagar gas limited generating fraud bills without proper meter reading for piped gas

Bhagyanagar Gas Limited is generating fraud bills for piped gas.
We are resident of Hyderabad and have two piped connections with different CRN numbers. The one with our tenants was not used since last three months.
BGL generated the bill for three months with exact same amount and same units of gas consumption for the connetions which was used and which was not used.
None of their executives visit monthly to take meter reading. There is no transparency in their billing process.
When asked about the discrepancy, neither they are showing the last month meter reading for the unused connections, not they are telling any justified logic of how the bill was generated.
They are fooling the customers. Kindly look into the matter.