The World Federation One Stop Fiqh

Ruling 2127

If a seller who has sold a commodity by prepayment is unable to obtain it at the time when he must hand it over, the buyer can wait until he obtains it, or he can annul the transaction and take back what he had given in exchange, or he can take something else instead [of what he had given in exchange]. And based on obligatory precaution, he cannot sell it to the seller at a higher price.