Who should I contact, please?

You didn't say if you take your medication daily or only as needed. My prescription bottle has the date the script was written, the date I had it filled, and the quantity in the bottle. Your doctor should have been able to get an idea from this as to whether you were taking your meds as directed or not. I also have chronic pain, and it is very hard to find a doctor who wants to deal with it. You might try going to a pain management clinic in your area, if you have one. They're there to treat people with chronic pain. Otherwise, I think I'd try looking for a new doctor. My rheumatologist treats my chronic pain because my primary care doctor won't prescribe pain medication, but if my rheumatologist didn't treat mine I would have asked for a referral to a pain clinic. I don't think there is anything you can do legally, but you would need to call an attorney to be certain.