Business Contract Attorney Licensed in USA

Hi, I have a client that has a business payment dispute with another company. Essentially, client worked as a consultant through it's s-corporation as a vendor contractor for another staffing company, who were contracted for their client (big company). staffing company approved timesheets every weeks for 5 weeks, and now is refusing to pay invoice. Can you help advise what to do in this case and how much would it cost ? Consultant is based out of Texas. This could be easy case and possibility to recover attorney fees and damages along with what is legally owed through invoices if you know where to identify gaps. All evidence is there through emails and digital timesheets approved. Please know that we are only looking for attorneys who know local law (preferably in Texas) and are experienced to handle litigation if needed.