Contact your seller and explain your concern.
Yes, a seller can mark an item as shipped before it is actually shipped and then correct the record.
He can even refund you after an item is shipped (which gets things even more complicated),
There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy.
Since both of you are being polite and friendly , the seller will probably send you a Mutual Cancellation. Confirm in your Paypal account that you have been refunded, then agree. This frees both of you from the transaction. Leave appropriately positive feedback and expect the same.
Yes, I'v read a book. Don't look so shocked- Captain Mal Reynolds.