经过三个月的投诉，我终于让百货商场经理退还了多收我的二十块钱。

经过三个月的投诉，我终于让百货商场经理退还了多收我的二十块钱。
【正确答案】：After three months' complaint, I finally made the department store manager return the 20 yuan lhey had overcharged me.