I did purchase the pair of shoes last weekend,but it broke already.上周末买的一双鞋子，已经破了。

I bought it last Sunday,but it broke now.上个星期天买的，现在就坏了。

Could you exchange it for me?你能帮我换一下吗？

This luggage is broken,I need to get my money back for this.这个行李箱坏了，我想退款。

I think the color isn't suitable for me,I want to return it.我认为这个颜色不适合，我想退了。

I suppose the size wouldn't fit me,I'd like to return it.我想这个尺寸不适合我，我想退了。

If it isn't suitable for me?Can I bring it back? 如果不合适，我能拿来吗？

I want to return it for a new one. 我想退了换一个新的。

If you show the receipt,I can take the items back.如果你能给我看下收据，我能接受退货。

I can refund it,if you produce the receipt.如果你能出示收据，我可以退款给你。

I need a receipt to give you cash.  我需要收据才能退现金给你。