Do you think I should refuse to refund a family member?
Why aren't you going to give your family member a refund?
My family treats me unfairly. I'm tired of helping them.
Sometimes family members can be annoying, but you should try to help them out whenever possible. If you refuse to help your family members, then you may damage your relationship with them. If you feel like a family member is taking advantage of your generosity, then try to set firmer boundaries without pushing them away.
Whose side are you on? My family is no better than me.
Even so, you should still accept the return. It is the right thing to do. If they return it to someone else they could bad mouth you to your coworkers.