Airtel — Amazon prime subscription not canceled

Hi,
I have called airtel customer care to cancel my Amazon prime membership subscription 3 days prior to renewal. Even I got message from airtel stating that my Amazon prime subscription has been canceled. But next day I got another message from airtel stating my Amazon prime membership is renewd and I will be charged Rs. 459 in my next bill. After receiving this message I called airtel customer care and asked why they are renewing my Amazon prime subscription plan as I have already canceled it. Airtel representative told me that due to some technical problem my Amazon prime subscription didn't get canceled so it got renewd.