hi, im not 100% sure , but i think you'll have to send a ticket to nitrado and ask for a refund.
this is the message they give you.
(Be advise, Nitrado xbox server can be only purchased on the Nitradop App on XBOX.)
so i dont think you can change to xbox ,as you can only get the xbox server on the xbox store.
hope this helps.
okay thank you for the advise ive just made an ticket hopefully i can get this sorted