Wǎnggòu de shāngpǐn yìbān qī tiān nèi kěyǐ wúlǐyóu tuìhuàn.
Goods bought online can usually be returned or exchanged within seven days, no reason needed.
Tips
culture
A shop sign reading 概不退换 means "no returns or exchanges". Online shops instead promise 七天无理由 returns. To return for a refund is 退货; to swap for another item is 换货.