There are probably multiple reasons why patients don't get the treatment they need. Among the reasons are: (1) Most doctors were never trained to treat fibromyalgia in medical school and aren't experts in it. (2) Even with an expert doctor it can be complicated to treat, often requiring a lot of trial and error and many months of effort. (3) The medications that have been approved by the FDA to treat fibromyalgia are not the most effective drugs, but are the most heavily promoted to doctors as well as the most expensive. (4) Certain treatments that some doctors have used successfully are viewed as controversial by other doctors and therefore not tried -- see the book, "From Fatigued to Fantastic" for one in very informative view on this, and (5) If when asking about pain relief you are referring perhaps to opiates, the scientific literature tends to claim that opiates don’t work or even make fibromyalgia worse. The studies and experiences that led to that conclusion may not be applicable to some patients. In one widely referenced study, morphine alone was used with poor results reported. That should probably come as no surprise, since opiates are not a good primary treatment for fibromyalgia, but may be effective when used in combination with other medications and therapies. In addition, other pain medications such as hydrocodone or methadone may work better for fibromyalgia as compared to morphine -- this has not been studied so far as I know. Despite the prevailing dogma, some doctors do use opiates on selected fibromyalgia patients and believe that in those cases the benefits outweigh the risks. However, this still tends to be a treatment of last resort after other options have been exausted.
I could go on and on about this, but will leave it here.