Salary arrears not paid by the employer

Sir, I was working full time with a multi-state Co-op Bank in Pune on the post of Manager. I had joined the Bank on December 2010 and resigned from the services of the Bank on November 2017 due to my personal reasons. I was satisfactorily relieved from the services of the Bank w.e.f. January 2018. Please note that I was a confirmed permanent employee of the Bank at the time of resignation. I am raising the query regarding non-payment of my salary arrears by the bank. Bank had executed Memorandum of Understanding (Hereinafter called MOU-salary structure revision agreement between Employees Union and Employer) dated 30.07.2016 for the period 01.04.2015 To 31.03.2020. As per the terms of the said MOU, it was applicable to those employees who are physically present on the payroll of the bank on 30.07.2016 on full time/ part time permanent basis. Since I was physically present on the payroll of the bank on 30.07.2016, said MOU is lawfully applicable to me. It is more than 3 years and still I have not received my salary arrears which are lawfully due to me and for which I have already given my services to the bank. Salary arrears are pending for the period of 15 months (April 1st, 2015 up to June 30th, 2016). From July 2016 onwards Bank started paying as per revised salary as per the above-mentioned MOU till I resigned from the job. I have taken follow up with the HR department of the Bank, however they have replied all the dues are cleared by the bank and nothing is pending. Moreover, they have threatened me to defend the case in the court at my expense if I complain to the regulator/Government authority for the same. Sir, please guide me what option is available to me to recover my hard-earned money as a citizen of India who has served the Bank with honesty and integrity. Also, I would like to mention that bank has not paid arrears to all those employees who have resigned from their service.