why is it so difficult to sync contacts???

why is this so complicaed and what is the point of the icloud sync of if doesn't

I have abou 180 contacts on my iphone 5....I have icloud set to sync contacts..so, on my ipad..I only have about 35 contacs (ipad is also set to sync with icloud

why aren't my ipad and iphone in sync?? isn't that the purpose of having my stuff in the icloud so I can access it from all devices??