Trai — exorbitant isd call charges by airtel

Address:

560011

I had made isd call to australia, airtel has billed an amount of rs4680/- for 26 minutes o[censored]sage, which works out rs180/min as per their bill amount, and they are not willing to furnish the isd call rate per minute in the bill. When enquired they r giving all irrelevant answers, actual isd rate is rs 12 per minute, as informed by their customer care officer,
Lot of communication has happened by mails from me and little staff, but still they say it is correct and you have to pay the bill amount,
I want to appeal against this and file a cheating case against airtel telephone service provider,