Summoned by labour commission

I have been summoned by three people who used to work in my small scaled workshop , as tailors , to whom I have paid them regularly and have record receipts of each payment done via online mode , due to blackmailing I have terminated them not at once but in different months . They have now summoned me from labour commission office in delhi ,for not paying them for a certain period of 2-3 months , to which they have not submitted any evidence or proof for being employed by me(for the disputed period ). I have been receiving union notices and have been going on dates to labour commission office based in kalkaji for hearing in front of conciliation officer. No conclusion has come out so far as the union people are unable to submit any proofs or records of these employees being employed by me for the disputed period and the harrasment has been going on since three months of reissuing new notices . They have also accused me of minimum wages act , offer letter , termination letter and esi etc . Please suggest and help what should be the best solution to this , as these people just wants to extort money without any valid evidences or proofs .