I'm assuming that you mean the ignition key won't turn, the car won't start and it won't come out of park. If this is not correct, please clarify the symptoms.
This is usually caused by a failure of the ignition lock assembly, and the entire ignition lock assembly has to be replaced.
We can order a pre-coded lock from Volvo, but a much better way to go is to take a standard lock and have it re-keyed to your ignition key.
To do this we would need the car, and your keys. Downtime is approx 2 days.
Mark's Independent (818) 718-6138