Cat meows day and night

My boyfriend and I just got a very vocal cat, he's lived with us for about two weeks. He meows just about all day and night, and we are trying to get him to stop waking us up at night. Ignoring him hasn't seemed to work, he meows whether or not we are paying attention to him. We used to have the bedroom door open at night, but he would wake us up constantly. The only thing we've found to work even a little bit, is opening the door and swinging a pillow in his direction (doesn't leave the hand, doesn't touch him at all) and he will run away. Sometimes he will stop for a minute or two and start meowing again, sometimes he will stop enough for us to fall asleep. He also has some automatic toys to keep him busy at night. Our next-door apartment neighbor has indoor-outdoor cats, and if he sees, hears, or smells one of them he goes and screams at the front door. He yells all day for no reason, even if we are actively petting or playing with him he is meowing. The only time he's really quiet is when he's asleep, and we're pretty sure he sleeps most of the day when we are both at work. Please help