How can I convince my landlord to tent my apartment?

I've been having a cockroach problem for the past year and my landlord has his agency deal with my problem. The agency has been sending out a professional to spray our apartment. He's already sprayed 3 times, and I'm still seeing cockroaches. Is there anyway I can convince my landlord or the agency to tent the whole apartment complex? I'm not the only person dealing with this problem, some even have it worse than me.