The question pretty much says it; I tried a couple of gas stations and stores but didn't find anything; I'm in Istanbul Buyukcekmece zone/
You can find them online if you search for "Kamp Ocağı". Hardware stores in shopping malls like Tekzen, Koçtaş, Praktiker will most likely have them. Also Decathlon stores sell them on their camping section with tents and sleeping bags. Ask for stock by calling before going to store though.