The more I read about TKR's in the US, the happier I am having had mine done here in Australia. The (lack of) pain management over there is truly barbaric and I'll say a prayer tonight that your doctor has an especially warm accomodation in the afterlife.
It's not the norm here and that level of pain is also unacceptable here. If it were me and the surgeon wasn't forthcoming with a new 'script, I'd be seeing your regular family doctor and if that didn't work I'd head for the local emergency room.
Also don't play brave and stoic, if they ask your pain level don't hem and haw and tell them 5ish or around 6, tell 'em it's an 8 or 9, don't be afraid to show some emotion. The squeaky wheel gets oiled. You need to do two things - be an active advocate for yourself and COMPLAIN OFFICIALLY when your needs are not met. Hospitals, surgeons and doctors have to explain complaints and how they rectified them to the quality assurance groups. They hate the paperwork complaints genrate so make them do their job to avoid it. If you get stonewalled immediately ask for their official complaint procedure.
You are being put in a horrible position, don't put up with it.