Hi Georgina,
I had the same problem.
Just bought a new case on ebay.
http://search.ebay.com/_W0QQsassZyinyinnewtech
So that is problem 1
But that's only where it starts.
Now you will have to replace the case.
Disassemble and assemple.
You'll need a special screwdriver to do that.
Cost you a few bucks (they call it a tripod or triwing).
You will also need a tutorial
http://site.powergamingparts.com/RepairNDS.html
So that's where I stand at the moment.
Waiting for the screwdriver to be delivered.
Cheers
tsabre, April 2008