I worked for Mastec in '06. I quit after 6 months and $600 in chargebacks later. All jobs were to specs. There excuse was either "customer education", which is B.S., or install related, which is even more B.S. In the end I found that alot of these tc's were equipment related. I quit and vowed never to work for DirecTv again. I have turned down countless job offers as a contractor, simply because of these ridiculous charge back's. Run away now, as it's only going to get worse. Good luck.
This is CABL.com posting #261908. Tiny Link: cabl.co/mbgiu