OP wrote:
"I was trying to format my Lacie drive but instead I restored it... It was divided in two: Lacie Share (with about 400 GB) and Lacie (65GB). Now I have a Untitled and Lacie, both with 65GB..."
I may be wrong, but it looks like you may have "wiped out" everything that was previously on the 400gb partition.
Or, at least 65gb of it.
If there was data on "the rest of" the 400gb partition, it might be possible to get at it using data recovery software.
"DataRescue" by ProSoft has a very good reputation for this.
Here's one more reason why I would not recommend Disk Utility for "duping" or "restoring" drives.
Use an app like CarbonCopyCloner or SuperDuper instead. It provides a more graphical display of "what is about to happen" so that the user will have a better understanding of the consequences involved...