退款单 meaning in English

credit note
refund order

* master sets include business card , envelope , expense report , fax cover , gift certificate , brochure , flyer , postcard , inventory list , invoice , letterhead , newsletter , party invitation , price list , purchase order , quote , refund , shipping label , special offer , statement , thank you card , time billing , web home page , weekly record , and " with compliments " card
* “大师集”中包括了名片、信封、支出报告、传真封页、礼品证书、小册子、海报、名片、库存清单、发票、信头、新闻稿、聚会请柬、报价单、订单、报盘、退款单、发运标签、特别提供、报表、答谢卡、时刻表、 web主页、每周记录和“致意”卡。