Vodafone — generating bill for mobile number asked to discontinue

I raised a request to discontinue my number in May, and in October they generated the bill for the same number and barred outgoing of the alternate number. While asking for the reason they said due to my negligence and sending a mail on wrong email id it has been done. I had to settle the bill for the number i had not been using for 5 months to continue services on alternate number. Again after 15 days they generated the bill stating I had raised the request to discontinue the service after the billing cycle.
I paid for the service i did not even use, and again they have generated the bill for a service which i have not availed