Indraprastha Gas Limited [IGL] — bill issues

Sir,
I am runjhun rustagi. It's a bill issue we have already paid the last bill on 3rd april.2017 of rps.997. This time we recived the bill of rps 1748 this is for 3 months. The amount is too much and printed bill we have recived its showing the previous amount also added into the current bill and the previous bill is already paid and amount is even deducted from our account we have that recipt too. And your coustmer care service is extremely bad whenever we try to contact the person pickup our call and says the surver is down and its continuosly happening since last 4 to 5 days and manier times no one pickup the call we are so disturbed and facing problem because of your services.
This time if this bill issue happens again i am going to take strict action against this because we have been facing this since long and again and again.
Kindly take action for this. Waiting for your reply.

Regards
Runjhun rustagi