Long delay in civil contract bill

Myself & my friend started a construction in march 2016 in visakhapatnam .We hired a contractor as myself and my friend are married women(both civil engg)who cannot go daily to site work(srikakaulam dist) due to our responsibilities.Completed the first small sub (civil)contract project successfully.In aug-sep,2016,we took much a little bigger sub contract project from PSR contructions(which is a sub contractor of Gayatri constructions pvt ltd),which is regard. constuction of retainging wall for a length of 400m on Nagavali river in srikakulam town,andhra pradesh.Although,we have completed 200m length of retaining wall ,we have received a payment of only rs5lac in May 2017 for first 100m only(deducting cement bags cost).The nagavali retaining wall project was stopped in jun-july 2017,by all contractors due to a long delay in bill payment.from then on we are asking for our balance bill payment,but there was no proper response from Psr contructions.Initially,Psr,said that government should release the bills.The ap govt have released the bills in march 2018,but still now we havent received our bill payments.we need your suggestion as to how can we get our bill amount?what is the procedure to file a complaint on Psr firm?