Reliance Communications — unauthorised billing

Reliance no. [protected]
Relationship no.[protected]
I have been paying regular bill for a wi pod device though it was not in use since more than a year. Since jan-feb 2018 i decided to request cancellation of the wipod. I checked with others & i was told that jio will take it up. But finally, i chose to write an email to customer care rcom, that their web world outlet, where we are supposed to go for cancellation, has been closed down. This was sent on 13th march by email. No response from them. Now i got a bill amounting to 4381/- (3798.83/ as pending amount & 582.39/ for the last bill). The previous bill statement was sent to me for month of april (With pending amount 1062/- + 1556.82 as the last bill). I don't understand how monthly bill amount has changed when the number has not accessed the network for more than 1 year. Again i have sent an email, but no response yet.