I had tenanted my commercial property in Delhi 2 years back. That time the tenant told us that water bill is not generated in Delhi due to new rule by Arvind Kejriwal. I did not doubt him. Now, I have got the pending water bill from that time amounting to Rs. 50,000 approx. and got to know he was telling a lie and the water bill is generated for commercial property. Now, he is denying to pay the same saying "he used very little water". What can I do?