Mahanagar Gas — Need explanation or overcharged

My apartment is closed from last 4 months, then how come bill was generated for 1249/-.
I need a clarification for last 4 bills payment as in between my bill was at negative because last month bill was also overcharged which was adjustable but not clarified yet. Below is my CA no and also had attached you the pic recent pic of my meter reading.
CA NO :[protected]

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