Squid expert required

Hi there, We have payed someone to setup squid on our server. Initially it worked fine but suddenly hell broke loose. All the ip's still seem to work, and we can still log into them however we are having some problems. 1. All the ip's we connecting to are going out the default ip address. So no matter what ip we connect to, we still get the same external ip. 2. We are using the ip's to access Facebook. We are having trouble with cookies and user agents meaning that we cannot connect to facebook very well. 3. It seems thats the proxies are not 100% anonymous. We want these ip's to look as real as they possibly can, so no site can pick up that we're using proxies. I think that is, should be a easy fix for a pro.