Used car dealers cheated not clear the old pending chalan and issue NOC

Hello Sir/ Madam, My self Santosh I stay in mumbai, I have bought car from delhi Rohini area from high street car dealer rohini. Before making token amount I aks them to clear the old pending chalan of car and give me invoice copy too. He said the noc will not get issued without clearing this pending chalan so don't worry car dealer staff will get this clear from onwer and invoice will received along with NOC copy from RTO. They had given me temporary receipt of NOC which is getting post appy online and ask me to make complete payment. I request them to first clear the chalan Or I will pay that chalan and deduct from the actual cost which is fixed. But they said I can't make payment it should clear by onwer only and they will get it done and without this NOC will not issued. Post more than two month I have received NOC without invoice and post checking the pending chalan I was not clear hence I am following with dealer but not getting support for chalan they had provide me the invoice after lots of following but due to delay in submission of paper in Mumbai RTO they had charge me fine of Rs.30,000. Now even after making all payment of tax and delay fine still my registration is pending because the pending chalan not yet clear. My question is how the Delhi RTO issue NOC without clear the chalan? Why still strict action not take on onwer like suspension of license and jail for not clearing the traffic violations. How dealer doing such cheating with consumers