Generally speaking, there is no Biblical punishment for neglecting to perform a positive commandment; only transgressing negative commandments are grounds to be punished according to the Torah.
An angel once found Rav Ketina wearing a linen wrap, and he exclaimed, ‘Ketina, Ketina, a wrap in summer and a cloak in winter (apparently, neither of these had four corners, and so they were not obligated in tzitzit), and what is to happen to the law of tzitzit?’ ‘And do you punish’, asked Rav Ketina, ‘a person who neglects to perform a positive precept?’ ‘In a time of divine anger and judgment’, replied the angel, ‘we do’.
The Maharal explains that the reason the Torah does not ordinarily mete out punishment for neglecting a positive commandment is because the person did not actually engage in inappropriate behavior, he merely missed an opportunity to reach the higher spiritual level offered by the mitzva. In a “time of divine anger and judgment,” however, a person is punished because of the lack of effort towards self-improvement.
The Maharsha suggests that during a “time of divine anger and judgment” it is incumbent upon the religious leadership to strive to fulfill even more mitzvot that will serve as protection to the community. If they neglect to do so, they will be punished for their negligence.
Tosafot point out that the local Jewish courts have the ability to mete out punishments to people who do not perform positive commandments, and we can assume that Heavenly courts do as well. They argue, however, that that punishment only applies in cases where the individual is obligated in a mitzva like sukka or lulav and neglects to perform it. The case of tzitzit is different, because the obligation only exists if the person wears a four-cornered garment. It was not that Rav Ketina neglected the commandment; he was never obligated in the mitzva, since he did not wear clothing that needed tzitzit.