I think the ignore is best policy. Tit for tat never accomplishes anything so I think your choice is the best one. You also need to learn to lie to them, because they will not take well to being ignored. So if they need help, your sick, or you will be busy, don't give an inch, like Nancy said, Just Say No, no need to feed their addiction. (intentionally causing discomfort to others is an addiction of power/control).