What Causes A False Negative For Burtrans In Urine Test Result?

Question : I have been followed a pain management Dr. for 2.5 years now , I have 4 herniated discs and spinal stenosis , I have under went spinal injections every 2 to 4 months ever since and medication management , of a butrans patch of 10mcg Q weekly, Percocet 5mg 2 per day , lorzone 750mg three per day...I have been a model patient and NEVER...have not taken my medications as prescribed or asked to have them refilled before the due date, I have had an increase in my Percocet to 3 per day , due to an increase in pain, at which time the office urine drug tested tested me and today I received a phone call today that my urine tested negative for Butrans. The Doctor called me today to tell me that he is discharging me as a patient due to non compliance of the Burtrans....What do I do now??? I change the patch as directed and do everything the way I am directed....The Dr. told me he will not loose his DEA licensure over me and I told him I would like a repeat Urine test or a GC/ test or even a hair sample he told me it defeats the purpose and he will not and that I need to find another MD. Please Help...