Call the MSO and tell them you are in the process of putting a lien on the system for non-pay of the services provided for them that you were hired for and that the vendor that they paid that did not pay you refuses to answer your calls, reply to emails, im sure that will get them moving and find out why you were not paid.
This is CABL.com posting #293937. Tiny Link: cabl.co/mboC5