3句英文任你选

　　I'd like to exchange this sweater.

　　我想换一下这件运动衫。

　　I'd like my money back , please.

　　我要退款。

　　You can get a full refund if you have receipt.

　　如果出示发票可以拿到全额退款。

　　半个句型要记牢

　　get a full refund (拿到全额退款)

　　Tip: refund n.退款;退还;赔偿。refund还可以做动词，表示"退还;赔偿。