Recently Nokia made Navigation free atleast in India. However if you now tried to connect for free navigation it still asks for you go to the store. The reason for this is that Nokia has allowed free Navigation using Ovi Maps only on the new version of the software.
So if you have bought your phone couple of weeks ago there is a very good chance you are on the old version. What you need to do is go to the Nokia site and upgrade your version of Ovi maps to the latest version.
There are two ways of getting this done, one is to download the software on your computer and then Sync with your phone which would then automatically upgrade the version of Ovi Maps that is present on your phone.
The second option is to directly download the software to your phone and run it from there. However this would require a data connection from your service provider.
The link for downloading the software is here
If you want to get the map data stored directly on your computer you should go through this post.