iPhone music not updating on iTunes

Hi,

I have an iPhone 4S. Whenever I delete a song on my iPhone, I plug it into iTunes and the songs are still there but with an exclamation mark.

Not only that but nothing in my music gets updated from the looks of it on iTunes, including things like Play Count etc..

Anyone having the same problem? I used to be able to plug my phone into the laptop, open iTunes and everything would update.

Cheers