What specifically is the physio doing for your neck ? Range of motion exercises, spinal manipulations, muscle massage/work, traction, pressure point work, ?
We routinely suggest looking into an assessment by an Upper Cervical Chiro. Check out
www.nucca.org and
www.atlasorthagonal.org for a specialist near you.
Some general chiros claim to have upper cervical skills but I would be very cautious. The twist the head and pop the neck can be far to aggressive.
It also helps to learn posture disciplines. An injured neck will not heal without the patient taking steps to maintain proper posture, especially during rest and sleep. Icing the injured area is also good to help reduce inflammation.
Hope you can find a good upper cervical chiro.
My best to you.