Vodafone India — Asking for extra amount which is not due

Address:

400614

Hi,
Regarding my mobile no: [protected].
Before porting out, i had paid all amount at Vodafone store and even had paid some extra amount as per the instruction of Store executive in Navi Mumbai.
After that there was not outstanding amount i had received neither on email nor though call/SMS.
Now Vodafone people are sending me Legal Notice Email demanding for due amount(which is not due).

When i called them on their number, they are speaking rudely and misbehaving saying you will have to pay this at any cost.

Please help me here.