Bonus denied

I have worked with XYZ BPO company for 2 years & resigned in May'15. I have been denied certain monetary benefits(refer below) due to resignation which I think on moral & ethical grounds are wrong: 1) We are entitled to receive bonus for the last calender year in the month of march i.e. for the FY 2014 it is due & paid in the march month salary I also received the same but due to some computation error it has been paid less to me as discussed with HR. There has been a revision in the Bonus took place in April salary not only in our process but across the organization but the same has been denied to me Since I have resigned in April. Ideally on moral ground it should not be denied since I was not in notice serving period in march which is the bonus payout month & if something went wrong in the computation I am also entitled to get the same. 2) We also entitled to receive certain client bonus on completion of 1 yr of service with the client which I already completed on 19 april(Resigned on 1st april). This client bonus is covered by the agreement with the client & not as per organization policy. There is nothing in the agreement so far as I know that it can be denied if a person tenders the resignation notice. It simply states it is to be paid on completion of 1 year with the client which I already completed but the same also has been denied to me. Please advice me how to proceed further on this since I don't have much funds to proceed further on this & I am bound by the arbitration agreement with the employer.