Pls help me on this matter how to go about it. This thing is just too painful.

We work/serve a popular organisation In this same nigeria,the worlkm was given to contract and relive over 200+ of their duty.they give one month notice,give us staff clearance form to fill and go to each department to put stamp on if weather we owe them any.which we did everything.they promise to give us our pay off on check on 1st of may Last month and collected our I'd card on April 30.since then they have been prosponding date week by week. now on Thursday14 of this month they re saying we re not entitle to any payoff, after work/serving 15years,10years,9yr,8yrs the least 2yrs. And he said we can do anything,cos some mumu among us agreed to work with the contract company. Pls help