Hello, I Attend A Pain Management Doctor.. I Had Surgery

hello, I attend a Pain Management Doctor.. I had surgery in June 2018 on my Shoulder. I was given from surgeon oxycodone 5mg. to take as needed for pain. My pain management doctor gives me mathadone 10mg twice a day ( I have been taking this for 14 years) along with diluded 8mg twice a day. He drugged screened me in august 2018. The oxycodone did not show in my urine. That caused questions they sent my urine to the lab. I get a phone call on the day of my monthly appointment that I was being dismissed from the practice not to bother to show up for my appointment. Well this is leaving me without my medication. Withdraw has begun. is it to my understanding I should have been given a 30 day notice as well with the two scripts to hold me until I find another physician. I havent spoke with my doctor. all this was told to me by his medical secratary. any information will help.