It is pretty unlikely that a new doctor is going to prescribe 30 mg. Oxycontin for someone, even for a long term patient.
You don't say what your medical condition is, or the cause of your chronic pain.
In today's environment, even with well documented medical conditions, surgeries, regular compliance testing, years of treatment failures, most PM doctors are reducing the total daily intake to 100 mg of Morphine equivalent dosing for patients across the board.
Where were you getting your meds before? Your best bet may be to return to that doctor if possible, because even if you find one willing to prescribe meds, they are under no obligation to provide the same as the previous one did.