Regarding payment for labor that has been done........................

My father was a teacher in a school( WB Government) from 1989 to 2015. At the end of 2015, he got to know that at 2013 March his tenure had ended. There was some mistake with the date of birth in his admit mark sheet, which he did not know about. After roaming around for some time, we decided to give the extra money back to the government. This process took some time so we actually had to give money of around 2 and a half year's salary. After completing the money give away we had waited for the pension to start. But that process took so many years. It is 2018 November, yet the pension has not started although we gave the extra money to the Government long back. Leaving aside these things my actual query is that my father's retirement date is officially 2013 now. The pensions will be calculated according to that date. That means from 2013 March to 2015 December my father had worked but he did not receive any payment. Can he get his payment for work from 2013 to 2015?