Full and final settlement is pending

Hi Sir, I was working in a Sales oriented : National Distributor ( electronics and IT networking)Public limited Organisation. My role was to Manage and Develop Sales. Work duration is 3yrs. My settlement is on Hold since 90days now and my notice period salary and other benifits (entire settlement, experience letter and Form 16) is kept on hold and HR which is actually existing for namesake, is coming up after 60days after following up for settlement from my side stating that dues are in my name ( basically interest charged to the customers for delay payments ) the National distributor company collects or gets the 3 blank cheque collected from customers before management approves for any credit exposure. The National Distributor is not using this 3 blank cheques which were collected for security purpose. Instead pressurizing me after my exit formalities stating all non sense clauses. Pls advise. I am not the only person. This company is doing it to more than 50% of their employees and also dragging it for 1 yr or more and 50% will never get. It is really sad after serving whole heartedly for over 36months. They cheat us this way. Every month salary matters. No experience letter also.