unjustifiable compensation and benefits

i am working for more than six years as a project based employee, i understand the fact that i submitted nyself to follow the co-terminus contract but my deep concern is regarding the compensation for i am a minimum wage earner( 404php plus 22php ecola in an american bpo company and the newly hired is compensating 407php plus 21.84php ecola is this justifiable? and on our other department/projects had an increase and regularized in their employment. that is really unfair for us..i have triedraise my concerns but the management always says it depends on the budget constraints and if it is that so why our department has the capability to increase the salary of our superiors and add more man power of superiors while we are the fruit of the labor.. there is anyway to increase our compensation as a project based employee?

i am afraid there is no legal right to a raise, just minimum wage