Can I file a mechanics lien?

Hello, Our company, ACE Capital Engineering, has been subcontracted by a General Contractor in Texas to provide utility engineering plans for underground and arial telecommunications. The GC was hired by a large telecommunications company in Texas, and they (the GC) hired us for the utility engineering planning. After months of work and timely submittals of plans by our drafters, the customer and GC have experienced relationship issues which has led to the customer not paying the GC. Meanwhile, our company has preformed our responsibilities on time and submitted the plans to the GC and Customer, which are already being used for actual construction at this point. However, due to their conflict, the GC claims that it has not been paid by the customer for the work we have completed, therefore we have not been paid either for a total of +$250,000 of engineering drafting that has been completed. We are looking for guidance on how to submit an mechanics lien, or any other mechanism to help us get paid. Could you please let me know what we can do, if anything, in order to come to a resolution? Thank you