I think it is better to move the logic of updating stations to the services themselves.
So the  Service interace would have a method UpdateStations which would save the updated stations to the datastore.

This raises a question of whether the Service interface should also be responsible for listing it's stations, which will also require to save the service name in the datastore.

As a last thought, it would be nice to have an 'All' static method in bikeShareService that would return an array of all implemented services.

Thoughts?