When mates are'nt there for you......?

I've got a good mate who I really like hanging out with and when we do hook up we always have a real blast! he has a really gsoh and we have alot of laughs! The problem is that I feel I'm always doing the running and he does'snt reply to txts for days, so I feel he just is'nt really a dependable mate. Do real mates always return txts or calls quickly and feel you can call them whenever and want you in their life?