Matthew 6:1-4 (and beyond)
“Take care not to practice your righteousness in front of men to be noticed by them; otherwise you will have no reward with your Father who is in the heavens. 2 So when you make gifts of mercy, do not blow a trumpet ahead of you, as the hypocrites do in the synagogues and in the streets, so that they may be glorified by men. Truly I say to you, they have their reward in full. 3 But you, when making gifts of mercy, do not let your left hand know what your right hand is doing, 4 so that your gifts of mercy may be in secret. Then your Father who looks on in secret will repay you."
By reporting their every work, to get credit from the society, who in turn publishes it and brags about how much work they are doing, they are canceling their reward from Jehovah God.
What justification do they use, for reporting their service? No one else does that, yet many others (not JW's) are serving without recognition from men.