give someone his or her due
give (one) (one's) dues
1. To give someone the appropriate payment for services or work that they have done. After intense negotiations, the local government will finally be giving rural farmers their dues.
2. To give someone that which they deserve, which can be a reward or retribution, depending on the situation. Don't worry about those stool pigeons, we'll be sure to give them their dues. After all her hard work, I really hope the company finally gives Mary her dues.
give someone his or her due
see under give credit, def. 2.