In Yali supermarket you can buy a roach poison that comes in a covered plastic container with a hole that just allows the roach to get in, eat, get out and crawl away to meet its fate. You can also get a private exterminator, as I recall he works in the Belediye. He has a poison that he sprays or paints on the floor near drains and areas where roaches enter and it gets them all. We did this the one and only time we had this problem and it worked miracles.