What is the correct action if an amount was paid to purchase gold, to be received after a week, and is it permissible to pay the same amount again upon receipt, then reclaim the amount paid with the receipt to correct the transaction?

It is not permissible to purchase gold by paying the price and delaying receipt, as this constitutes usury (riba). Immediate possession is a condition when selling and buying gold with paper currencies, in accordance with the Hadith: "Gold for gold, and silver for silver… hand to hand." Paper currencies are considered to have the same ruling as gold and silver. To correct the transaction, the receipt must be returned, the money refunded, and then a new contract concluded when the gold is available. If rescinding the contract is not possible, one may take the gold and seek forgiveness, for "whoever receives an admonition from his Lord and desists, he may have what has already passed."