Mahanagar Gas — billing on assumption

Address: 400051

I have already ecs payment of mahanagar gas (Pipe gas) domestic bill payment through my bank (Icici bank, thakur village branch) for many years.
Since we do not stay for a long time and visit for two months in a year our consumption of gas is almost nil in every month excepting one/two months in a year. Normally it works to rs.50 to 75 monthly because of minimum charges. Our ecs limit is rs.300.
Due to adopting assessed meter reading without taking the actual meter reading i found that the billing was done for more than 300 and impose penalty of rs.100 every billing cycle making it abnormally high. Recently i found that the bill was rs.441.91. Since i am not in mumbai currently i sought payment online. I had to pay rs.441.91 as i had no option.
My complaint is if the bill is raised every quarter it can not exceed rs.300 and paymet is made through ecs. Moreover when the flat is locked for 10 moths continuously how the assessed meter reading will be multiplied every quarter? As a disciplined customer i paid the assessed bill but i request that the method of assessed meter reading should be reviewed and arrange to refund the excess amount of bill with the penalies recovred from me.