Contingent Services Scott Campbell Performed two jobs, did not get paid, contacted them, gave them what they asked for, still no pay, leaving messages, no response Internet

Contingent services dispatched me to perform technical services at wells fargo banks and some other garage door business that was having phone equipment problems, wells fargo I relocated a fax line, completed the jobs, documentation, signatures, happy customers.  Months go by, no pay, sent W-9, still no pay, and now no one calls back, can't figure out how to get paid for services rendered, contingent keeps transferring me to a Scott Campbell who does'nt answer phone or return calls.  I'm getting ready to give up, but might consider doing more research.  Looks like I will have to make more calls, get demanding, ask for supervisors, more transfers, going in circles, what a pain, not deserving of someone that provided excellence in service to contingents customers.