The host was missing the entire 5 days. I've been to Istanbul before and to similar flats near Gelata. The flat is fine, but we had no airconditioning at times, no cleaning service, broken blinds, had to leave windows open with clubs blaring into the night for air, and only 2 towels for the entire stay. The host would not answer his phone or respond.
There are many similar options for the same price in Geleta. Go for those. One where the host is present at least.