an amount of money that is given back to you, especially because you are not happy with a product or service that you have bought

I took the radio back to the shop and asked for/demanded/got/was given a refund. 我把收音机拿回商店，让他们退款／坚决要求店方退款／得到了退款／他们给我办理了退款。

to give someone a refund

When I went on business to Peru, the office refunded my expenses. 我到秘鲁出差，费用由事务所报销。

[ + two objects ] The holiday was cancelled so the travel agency had to refund everybody the price of the tickets. 度假行程取消了，所以旅行社不得不把票款退还给所有人。