The 1000, which was handed in before the opening, told the developer that it can be returned if you don't buy it after the opening, but the agreement and receipt of the intention payment have been lost. Can I return it? This is completely refundable. After all, you paid the intention money. Even if your receipt is lost, as long as you have a POS receipt, it can be used as proof of your payment. I suggest you apply to the developer by hand, explain the situation in the application, and then give the developer a receipt when you refund. The average developer will not deny it.