What is the return and exchange policy for this item?

这个商品的退换货政策是怎样的？

同一单元的其他句子

• I'd like to return this item because the size doesn't fit.我想退掉这件商品，因为尺码不合适。
• Could you check if this item is in stock?您能帮我查一下这个商品的库存吗？
• The zipper of the jacket I bought last week is broken. Can I exchange it?我上周买的外套拉链坏了，可以换货吗？
• Is there a more detailed manual for this product?这款产品有更详细的使用说明吗？
• I'd like to compare the features of these two models.我想对比一下这两个型号的功能。