Pain pump failure

I had the Medtronics pain pump implanted a year ago. Nothing else had worked to relieve my severe lower back pain which radiated down to my buttocks, legs and feet. My spinal cord stimulator also stopped providing any pain relief. I had the pump output increased six to eight times with just a few days of decent relief. Then we moved to another state. New pain doc has increased the output 5 or 6 times. With my pain still hovering between a 7 and a 9, I was desperate. I took an old oxycodone which actually helped. But the pain amped up after a few days so I went back and he upped the dosage by 30% (quite drastic). By the end of the day, The pain had turned into a numb feeling. That night I could not sleep. I was on the verge of nausea and felt like a zombie. How much dosage is too much? I am still in bad pain unless I give myself a bolus, which sends me back into the numb, zombie state. I am afraid that I am in an overdose situation. My voicemail to the doc with these concerns has gone unanswered. How can a pain pump not relieve pain at this level? Really looking for someone with similar expereince and what you ultimately did.