Neighbor's retaining wall is causing water problems?

My neighbor, who lives uphill from me, built a retaining wall 3 1/2 years ago without a permit. The wall is 4 feet high and extends about 40 feet along my property to the back corners of our properties and also about 30 feet in - kind of like a 3 sided rectangle. When he asked before he put it up I told him I don't have a problem with it so long as it has proper drainage, done right and looks good. Needless to say, I am now stuck with a 4 foot high ugly cinder block wall with another 8 feet of solid white plastic fence on top of that - 12 feet of ugliness. The worst part of it is that I now have constant water problems because of it. After it rains, my yard remains wet for 5-7 days now as opposed to pre-wall when it would only be wet for a day or two. The wall slowly seeps its water onto my yard. I have spoken to him several times about this problem and finally last fall he put a drainage pipe that was supposed to divert the water to the street. Unfortunately, not a drop comes out of the pipe when it rains. I have spoken to the towns code/construction official and he says that there really isn't anything that can be done (which is nothing but pure BS). What are my options?