Lanlord wont take care of bed bugs

I live in Portland maine and rent a studio. I have lived here for almost 2 years and for the past 2 and a half months I have been being bitten by bed bugs every night. I was never told that the other tenats had them or had been being sprayed down for thwm until i mentioned the bugs to my lanlord. I guess this building has had it for a year. he told me to get a plastic sheet and that would solve it. he aslo said someone would spay it and he hasent followed through. all the neighbors have told me that they are going through the same thing what should I do?