Maharashtra Natural Gas [Mngl] — Wrong bill with late charges

The late charges of Rs. 100/- are levied without no reason in last bill. When I inquired, it was told that it was by mistake as the bill was generated late and will be reversed. However when i received the bill for this month, i so no reverse of late charges. Please look into asap.

I raised the issue through mail to customer care and also called but no response.