Before the conciliation officer, an individual workman can contest the case of his termination. All other cases have to be contested by the union or substantial number of workmen.
Your problem pertains to "subsistence allowance", which can be challenged under Section 33 -C(2) of Industrial Disputes Act before the labour court by direcly filing application. There, as an individual, you can contest the case.
Other-wise, you can file a civil suit for recovery, which is a little bit expensive.