I have relocated to Chennai from Mumbai.
My Mumbai No. is 9867363300. I took a new Airtel No. in Chennai.
I called from this new no. at 121 for disconnecting the old no. on 121 and got a ref no. 16614863 on 8th May.
Despite following up again on 10th May, no action has been taken as yet on the cancellation and Airtel continues to charge me for the old no.