I had bought a new gas stove. The old stove was to be taken away at the same time the new one was going to be delivered, so I needed someone to come to disconnect the old stove, then return to connect the new stove.
I called Cambie Plumbing and they said they did this kind of job quite often, and that they had people properly certified to do the work.
The gas fitter came at the scheduled time to disconnect the old stove, then returned later that day to connect the new stove. He was very professional, had all the proper equipment including a gas detector, and did a great job. Total cost was $125 plus cost of parts.
I would recommend Cambie Plumbing if you are looking for someone to properly connect your gas stove. A lot of appliance installation/repair places will not (or should not) do this kind of work because they are not properly certified.