Reliance Communications — fake billing amount from r.com

I have submitted the total bill and closed a sim, after one year i am receiving calls and mails that there is payment balance which i have not payed.
But i have already paid total payable amount and my sim was closed.
And now,
Again and again i'm receiving mails and calls from r.com
Veryt bad experience with this connection of r.com, i m done with this communication company.