serviceforce usa upon completion of contracted work service force has failed to pay us despite repeated attempts dulles, Virginia

Capital City Paving, Inc. of Concord , NH was hired by ServiceForce USA to complete paving work for one of their customer, First Student (bus company) in Belmont, NH several years ago.  Upon completion of the work, no complaints by anyone, ServiceForce USA failed to respond to our invoices, failed to return calls and never paid us, $9,950.00.  Our Attorney was given the case and we filed and won a judgement against them in NH Courts.  Despite this verdict  we can not collect since out of state courts do not respond to judgements in other states.  Our Attorney continues to try and reach an agent of this company through the Sec. States office but has had no luck, not working in NH anymore???
 
This is nothing more than legalized theft. How this company can continue to conduct business is beyond belief. Any help?