Vodafone Idea Limited - Extra bill charged after port out

I used Vodafone for more than * years, paid each bill timely and now when I have ported out of their network due to pathetic network services and non resolved complaints, they are charging me extra.

I paid Rs ***. ** as the monthly bill from last year. I ported out my number on **th and I left their network on that day. I paid Rs. *** as the advance bill for June month ( I used their services for ** days only, *** is the bill for ** days).

Now I have received an extra payment request for Rs. **. Which should have been given back to me as I paid Rs *** as the bill for ** days of June instead I am being asked for an extra payment of Rs **.

I have searched on online forums that this is a kind of cheap tactics played by their company whenever somebody ports out of your network. I am also not been able to see my detailed bill for July month. There is no attachment of the bill as pdf. I tried from Vodafone website also but there also the mechanism doesn't work (maybe due to my port out into another network).

PS: It seems they have removed my registered email address from their directory so that I cannot mail them. This is the height of disservice any company can do it its customers or past customers.

Not to mention year of pathetic service, mental stress, frustration, monetary and productivity loss has been huge which I am unable to out into a numerical value. I wasn't able to port out earlier as I had a busy schedule and I was staying in a different state of India.