Adjust Rewards Left in Fundrisig Plugin

I have received two donations for rewards which were withdrawn later. I've deleted the withdrawn donations from the pledges list. But the rewards still count these donations. Initially there were 8/8 rewards left. After the two false donations came in it was 6/8 rewards left. After deleting the two false donations it should be 8/8 left, but it is still 6/8 left. How can I reset this donation counter?