Recourse When Dealing With A Pharmacy

In a nutshell my wife has been seeing a psychiatrist for ~6 years, has been diagnosed with agoraphobia, chronic ptsd, Anxiety etc. she has been on the same few meds with minor adjustments for nearly 5 years now and it’s done wonders for her quality of life. One of these meds is a controlled substance for her anxiety. When she went to pick up her usual refill this month a pharmacist pulled her aside and said they will no longer fill her prescription for the controlled substance unless the doctor sends in a new Rx and a plan to taper her off completely. She was pretty shocked at this news and asked why and they told her it’s nothing to do with her but they will no longer fill Rx’s like hers for longer than 3 months because of all the lawsuits around opiates (which her Rx isn’t).
My question is, what recourse do we have? My wife in no way abuses her meds, but forcing her to change a treatment plan that is working for the sole purpose of legally covering their butts feels like malpractice. She has an appointment to discuss this with her doctor this month but any advice on what recourse or avenues to look into in this matter would be extremely appreciated.