Vodafone took a 1,500Rs advance from me and did not apply it to my bill.

The 1,500Rs advance was for new data plan I took in October.
It was supposed to cover the first 3 months of Nov, Dec and Jan.
I have a receipt for it.

In the Nov bill, I was charged the full 650Rs rental for data.
The advance was not applied.

I tried to resolve this at the Vodafone store (Thakur Village) on Dec 10th with my receipt.
Store manager Abhishek Arulkar was not very co-operative.
He told me that the rep that gave me this plan (Ankur) was asked to resign for offering invalid plans.
Told me that my data plan was not valid.
He did not apoligize/compensate or offer a refund.

After arguing with Abhishek, he told me he would give me a credit of 1,500Rs.
He put in a store request and gave me the request number.
Said credit would not apply to first bill.
So I had to pay the Nov bill in full, even though I paid an advance for it.

Dec bill came around and promised credit was not applied again.
I called Vodafone Care on Dec 28th to resolve this and spoke with supervisor Arif Sayyed.
Arif told me that the Vodafone store did nothing about my earlier store request of Dec 10th.

So I put in another request on Dec 28th via email to Vodafone Care with scanned copy of the receipt.
But nothing's been resolved yet.
I've added Appelate Authority and Nodal Officer in the email thread.