Give the cable company a call, especially if you paid for installation.
I told the cable company that I would not pay if the technician that came out to install, as REQUIRED by the cable company, could not hook up to my display device without my help.
I ended up not having to pay when the guy looked at my projector and started scratching his head.
When I moved to my apartment they just handed me an HD box and told me to call them if I had any questions about how to hook up the HD/DVR set top box. Never needed to call, it is REALLY straight forward.