Leave enchasment money not paid

Sir my father served in indian railway for 10 years and aa per rule maximum 30 days of leaves can be enchased in a year therefore 30*10years = 300 days. while in army he served for 26 years and during that 26 years he has enchased 300 leaves and got paid for it at the retirement. But at the time of retirement in railway, settlement board denied to give monetary benifit to him giving reason that, he has already availed 300 days leave enchasment in last service that is army, so leave enchasment amount in respect of service in railway can't be paid to him. Sir he had enchased 300 days leave from his entitlement every year and it was not done in a single day, leave enchasment in a govt service is done at the end of every year, at the time of enchasment i.e at the end of every year nobody told him that he won't be getting paid for these leave enchasment. He has reached many officers of account department but nobody helping him while from his friends he get to know that they are paying leave enchasment amount to some ex service personnel who are posted in account department at different HQs of railway. Sir this is unfair. Can you help what to do