Transaction 1814652997160240 is a test donation of 125 JPY, cid=15580017. When we went to refund at Adyen, the transaction amount there showed as 12500, and we inadvertently refunded the larger amount. At first I thought this to be a display error at their portal (no decimals) but Luke at Adyen responded:
JPY is a currency that has no minor units in practice, so the amount of the transaction as submitted to us in this case is actually 12500JPY. If your records indicate that the donation should be for 125JPY, then there may be a mismatch in the way your system is treating JPY versus more standard currencies. Can you have your developers check to see how they're handling non-standard currencies like JPY? Other relatively common currencies that lack minor units are KRW (Korean Won), CLP (Chilean Peso), and VND (Vietnamese Dong).
It looks like the same thing happened to 1814653038148723 and 1814655234138861, also from the same tester. Can we determine where this error occurs and make it so the amounts match?