Sorry for any spelling or grammar errors, I got very little sleep.
What is causing them to wait and for what are they waiting? I've never experienced a "wait" situation in civilian care like you are describing. I have at the VA, but never in civilian medical care. The only wait is usually getting an open operating room to do the surgery in. Usually, most Urologists I know do their surgeries one day a week. If that's the wait you are talking about, then that's normal, but I got the impression from your post that this is not what you are talking about.
As far as getting stronger pain meds, you need to call and talk to your physician and explain the pain you're having and that your present pain meds don't help it and you would like a stronger dose or a different pain med. If your doctor handles kidney stones, then they surely should understand your situation and the pain involved. Ultimately, it will be your doctor's choice though. We wish you all the best with this problem and hopefully, your surgery will happen soon and it will be over. We've all been there and "feel your pain".