Principal Contractor not paying sub-contractor after getting the job done

As sub-contractor we executed mechanical job for a Delhi based company under a PSU premises in Maharashtra. The work had several interdependent activities executed by other agencies also. The job suffered on account of 1.5 month covid19 plant lock-down, 8 month late civil foundation by civil agency & 2 month delay by grp lining of principal contractor. We completed their job anyhow keeping our resources at site all this time at severe additional cost based on assurances/mail/whatsapp. Before job completion we even submitted our loss claim which they never responded. They kept on saying first to complete the job & then talk After job completion we submitted our last bill & also demanded loss claim which was unheard rather they kept our last bill on hold. We also complained this with PSU but no relief till date. Finally we issued Legal Demand Notice against our loss claim & filed online application in MSME against the bill amount. Its been 2 month when MSME registered case temporarily & issued notice but is yet to register the Case permanently. Its the same company on which we had filed a criminal case in 2015 upon cheque bounce & thereafter never entered in business but they are now part of foreign business group & hence we moved again. Such loss of income has disturbed the whole business. Now don't know what else to do to create pressure upon them & recover. We feel cheated that they got their work done & left us to decimate. Can police complain be filed in such matter or only civil suit is applicable