Vodafone India — getting bills in spite of not using the number

Gavin here... I had a postpaid number which i wanted to convert it to prepaid. I contacted mr aspak from vodafone gallery papdi vasai west. Was told to pay the pending bill of rs 250 with service charge. I made it clear just tell me the exact amount and convert my number to prepaid. Again received call from them to pay rs 150 i event paid that in the month of march. The took no action and i enquired about it they told your rs 100 is pending which frustrated me and requested to close account. I got mail on july that 745 bills is pending and i went to the gallery and they assured me that i have to pay nothing as number is not on use and they will cancel it. But i m getting phones from the bill clearing team of vodafone to pay the amount or go for a settlement which i disagreed as number is not in use and i have requested to close the number a long time back. And they told to go to the store on 9th august 2017 as new bill will be generated and than they can settle. I should not be paying any amount as i had requested to close the account and i have not defaulted anything as i m not using the number at all