I got a new iphone and when I synched it with itunes it doesn't work anymore?

Ok got a new iphone it was great loved it. Then when I connected it with itunes it said synch as new or from old. I said old cause i have an ipod. And it synched. But now my iphone is so slow like it sucks. The calling feauture doesn't work sometimes. And text messaging lags.

Is there anyway to fix this

Apple.com

Bring it into apple and ask for them to fix it