you can ask your municipality(BELEDİYE) if that building having a permision or not. we have an ACT (right to information). acording to this act(law) you can ask that builging is legal or illegal and your municipality(belediye) must response. if they not response your ask you can go court or publıc presecutor. i can recomended in your aplication you should ask that building if having construction in that permision or not.
if that building have a permision then you should sue