Can a booking made with an Avios-LeShuttle voucher be cancelled, refunded, transferred or exchanged?

This will be dependent on the ticket type you have purchased in line with LeShuttle Ticket Terms & Conditions. On refundable tickets, for any bookings cancelled after booking, the refundable element will be provided in the form of a LeShuttle Credit Voucher. The refund will not be in Avios.