Airtel — Repeated calls of nonpayment for payments made

I Archana Gupta hold two numbers ( [protected], [protected]) of which the payments were made and still I am getting repeated calls from airtel call centre The details of this is in the photo that I am uploading . First time the payment was made online from airtel website, later they said that since I have changed the plan the payment went to your existing plan So again, under the guidance of one of the airtel executive I made the payment through visa bill payment site ( as guided by the concerned person) on 19 May 2015 .PHOTO UPLOADED OF THE ACKNOWLEDEMENT RECEIPT After that I started getting constant messages and calls from airtel for non payment of bills. They acknowledged that the mistake was from their end but have asked me to make payment again by visiting their airtel shop as the payment has again gone to the present plan! Now the call centre people are giving me threats that if I don't make payments by visiting theirs centre they will disconnect my phone In my present family plan there is a credit balance as the payment went to this account( phone number [protected]).. This has been a mental torture for me for past one month. I have been prompt in my bill payments Kindly help me in this matter .