From their (very) small print:
Note, when purchasing a ticket promoted by Atlantic Star Airlines a contract will exist only between the passenger and TravelPack. There will be no contract between the passenger and Atlantic Star.
We are very pleased that Solomons of Saint Helena continue to support the Atlantic Star proposal, but wish to point out that in joining the Priority Club through them you are not entering in to any contractual relationship with Solomons. Solomons are kindly making it easier for island residents to pay the joining fee and they accept no further liability.