credit note
noun [ C ] UK uk/ˈkred.ɪt ˌnəʊt/ us/ˈkred.ɪt ˌnoʊt/ (US store credit)
换货凭单，信用票据（退货时商店给的票据，可用于换取等值的其他商品）
a piece of paper given by a shop when you return something you do not want, that allows you to buy other goods of the same value