Seniority status in south western railway Bangalore

Sir i got appointed on 21.5.2007 and another person appointed on 20.8.2008 of same panel but employment notice no.2005 but my employment notice no.is 2006. The said employee on his own request joined late to service in railways as assistant loco pilot behind me. But as time passed my self promoted as senior assistant loco pilot in 2010 whereas he promoted in 2011 but now he got promoted as loco pilot/ goods in 2015 where as myself promoted in 2017. This is how administration favoured him to promote as loco pilot/goods earlier to me even though his appointment is behind me, training also behind me,date of birth behind me, date of entry into cader behind me. Marks scored also less in training compared to me. This I could not understand and I gave representation in 2016,2017 years seniority list prepared in 2010,2013,2017 clearly mentioned that the said employee joined late not joined in time and requested to join late. So I request you to suggest sir can I get back my seniority.