Airtel — again payment issue occur

Address:

380059

Kindly check this invoice and mail from your side.
As per this mail we made payment of rs-6862 after adjustment of 2171.89 (Wrong sms charge).
Now in new invoice payment amount is-6087+2172=8259 rs.
Now what will we do?
After again and again complaint no one is answering for this matter. Now we have solid proof that the airtel people mail us from their official mail id but now they change their commitment.
Please resolve our problem urgently.