The URLs mapped as Internal Url of AAM redirects to Public Url while accessing

Hi All,

I have created a web application in Internet Zone with the url "http://new.site.com". Then used that url as public url and mapped 10 internal url to it. The internal urls are like http://new.site1.com,http://new.site2.com,http://new.site3.com,http://new.site4.com,http://new.site5.com,http://new.site6.com etc., 

The host headers has been added to those URLs in IIS also. When I tried to hit the http://new.site1.com, the address bar shows the url as http://new.site.com. The same case when i tried to hit all the other 9 urls. 

But I need the internal urls to be displayed in address bar if the user types it. Kindly help me to resolve this issue.

Thanks

Sowmiya S