Vodafone India — harassment regarding charges which I have paid already

I got my vodafone no ported in the month of april 19. After clearing all my dues on my vodafone no [protected] i was able to port my no successfully to airtel.

After one month after porting i got multiple calls from vodafone that i have some outstanding amount of rs 2000 which i am supposed to pay.. As i had already paid all the amount at the time of porting i was not sure what this amount was but to avoid any problems i paid the amount. Attaching the screenshot of the message that i received from vodafone representative to pay the amount and my confirmation on same.

Post that payment every month i was getting some frequent calls that there is an o/s of 500 rs on my vodafone no. One day i came across a mail conciliation process asking to pay the same amount. Not having time to get into these trivial things i just paid the 500 amount through the bill desk link giving in the mail.
Now again i am getting calls and mail to pay 503 rs. My no [protected] is on airtel since june 19, and i have paid all the amount due on vodafone even more, still i am receiving these call and emails which i perceive as harassment and extortion of money from customers.
I demand a explanation and compensation from vodafone on this