I canceled the shuttle that was booked for my package tour, but they won’t refund the pickup charge.

Shuttle vehicles are generally included as part of the package tour. Even if you cancel the shuttle, the cancellation provisions of the tour will apply. If those provisions state that no refunds will be given, you cannot ask for a refund. First check the terms and conditions of the package tour and the cancellation provisions, then present the request to the travel agency that runs the tour.