Reliance Communications — Number assigned to someone else while it was denied to give me back

I have reliance post paid number, which I have used for Bank, Aadhar etc. Then I closed the connection and travel abroad. Now I see the number is used by someone else. When I came back to India I asked reliance to get me the same number but the request was denied saying the service I was using is closed. I wanted to report to concern telecom authority and reliance. This is a serious matter. Kindly help me get my number on priority.

Reliance number used: [protected]
Contact Number: [protected]