Airtel - Airtel 4g dongle inappropriate billing

Sir/Madam,

I had taken Airtel Dongle-*G connection in the month of March ****. Dongle no. is **********. During July **** one airtel agent called me and requested for upgradation of existing plan as it has some good offers. Accordingly i accepted the request and one airtel agent visited me and collected my ID proof, photograph and gave new dongle sim no. **********. I discarded the old no., activated the new no. and started using the same. After one month of usage i received a message to pay Rs. *** due for bill dated **st August **** for the new dongle no. ********** but no hard copy or soft copy of the bill received. I made the payment for the same but no confirmation message received. Again after a week i received a message to pay Rs. *** due for bill dated **th August **** for old dongle no. **********. I was shocked to see this and called your agent who called me for urgradation request initially. She casually told that i had to give a disconnection request of old no. and asked me to contact customer support and give cancellation request. Accordingly i contacted airtel customer support helpline and told this issue. Moreover inspite of knowing that both dongle no. are registered with same mobile no. and address and also he told that new sim was not required for upgradation and could have taken the upgradation request on old no. itself and he asked me to pay the bill of old dongle no. After requesting to him that i have not taken any new connection and when they are upgrading the plan its airtel responsibility to cancel the old no. automatically, I thought it would be auto-cancelled. Then he connected the call to some other person and she spoke somewhat in a rude manner that i have to make the payment for my old no. and she can give a waiver of *** rs only and also regarding the bill she told the email ID is updated wrongly so the bill is not sent. Finally she took the disconnection request of old no. and asked me to pay the amount of Rs*** to complete the disconnection process. Accordingly i have made the payment. Then I mailed airtel customer care about the disconnection status and they sent an reply mail that the service on that no. Has been stopped effective from **th Sep **. Later again they have generated bill of Rs*** dated **th Sep and when I enquired to customer care about this they said the no. Is still active and after repeatedly arguing for about half an hour they accepted their mistake and gave waiver and took disconnection request again for both of my dongle no. In spite of all these again Bill of *** rs dated **th Oct is generated and I m really feeling stressed and called customer care they keep on putting call on hold and said that the no. Is active in between and they do no the cause and I have to pay the bill ..they keep on arguing about an hour.. I m really fed up of this and I m feeling unnecessarily stressed. Please look up into this matter