Indus Towers — I'm complaining regarding the rent that was supposed to be given

Indus towers (formerly Bharti Airtel ) had installed the tower on my site 15 years back but from past 2 years they aren't paying any rent to us .

Also, I would like to bring to your notice that the main landowner is 85 year old widow who is totally dependent upon the tower rent and the company of such huge stature is not doing anything to resolve the issue.