We'd rented out the whole ground level portion of our commercial building to a tenant about 7 years back. As they weren't strangers to us, we'd agreed on a lesser rent than what we should get. Over the years, the rent has not been increased significantly. Instead of paying Rs.35,000, we've been getting Rs.13,500. And now when we ask to vacate our property even after the completion of the contract, those tenants are demanding 15 lakhs to vacate our place. We told them that this demand would land them nowhere but in trouble and to this they retaliated saying that they've recorded what we've said and will get it to the police station and file a case on us. They've told very boldly to go and file a case as they're sure that the case will run for long and the property will still be with them. Now we're very confused and worried as to what we need to do. How should we react now? What should we do?? Please advice.