Xbox doesn't recognize new (official) HDD after big screw up?

So basically, I tried to transfer my data from a 60GB HDD to a 120GB HDD. I already have a transfer cable(lost the CD) so what I did was I put the 60GB one in my xbox, and the 120GB one in my transfer cable to my xbox. The xbox asked me to configure the new device and I agreed. Then a clean data transfer followed and I thought it was done. But what turn out is that my xbox actually configured my 120GB HDD to a 16GB external HDD! When I plug the 120GB HDD in on the top, it won't recognize it. Can I fix this or should i contact microsoft?