invalid inernet charges of rs 8000

Location/place: bangalore

Name of company/service: airtel

hi i am using 99 plan internet from airtel and they charged me 8000 rs for 1 month usage when i call they say it will be wayed off and when i got the bill the charges was applied and i tryed to complaint and they told it will be resolved and noe my connection is disconnected to my no 9972788688 who come they can do without mu knowkedge