My Neighbors Dog Craps in my yard. Help?

I live in a Condo Development and everyone is pretty good about cleaning up their dog mess. Well most of them. I have one neighbor who just simply lets her dog out and does not clean up and it craps every ones yard. I have knocked on her door and she acted like she did not know about it. I called condo ociation and they said they would send letter and they would be fined. Anyway i woke up today and low and behold their it was crapping in my yard. I went to the neighbors house knocked and they did not answer. Should i pick up all the dog crap and put it on the doorstep? What shall I do? Im pissed off at them and their disregard of others.