Unfortunately, you probably will continue to have trouble finding a doctor to fill it. When you find one, treat him/her like gold!
The problem, as I understand it, starts with Medicare. They don't pay to fill them. That means that private insurance doesn't pay to fill them. Most doctors won't do procedures that insurance won't cover, since they're not as likely to get paid for their work.
I was about to get a pump back in April of last year when the hospital that I was going through closed their pain management clinic. I'm pretty sure this had a lot to do with the clinic's closing. I finally got a spinal cord stimulator instead, just last week.
Maybe your dose needs to be changed? Or a different medication used? They told me that there are more/different medications that can be used, although since I'm not a doctor, I don't know if that applies to your situation.