Airtel — overcharged bill amount by airtel

Address:

Ernakulam, Kerala, 682030

I have been overcharged for my previous month postpaid bill amount. More over my bill amount is different in the text message being received to that of the one displayed in the portal. Airtel is cheating its customer.

Besides this issue, i have a current plan of 425 local+std wherein i have used only 209 min but ts been shown as overusage. Don't understand what these people really mean when i have balance minutes left and its been shown as overusage in the portal and being overcharged.

Kindly look into the matter.
Early response would be appreciated..

Didn't expect such things from airtel.
Attaching screenshots of my usage graph as per the portal for better understanding.