I can't help you without a proof of purchase.

没有购货单的话，我帮不了你。

youdao

You'd better keep the receipt as your proof of purchase.

你最好把收据收好当做是购买的证明。

youdao

Keep your receipt as proof of purchase.

保留好你的收据，作为购物的凭证。

youdao

Keep your receipt as proof of purchase.

保留好你的收据，作为购物的凭证。

youdao