something seems to have gotten screwed up, since liblapack-dev should be unpacked, but the error reported is that /usr/lib/lapack/liblapack.so doesn't exist. Did you try deleting something by hand?
Anyway an easy fix may be just to remove and reinstall the relevant packages. Eg
sudo apt-get remove --purge liblapack-dev liblapack3gf
When running this take note of any other packages that are uninstalled. Then reinstall the packages.
sudo apt-get install liblapack-dev liblapack3gf
and any other pacakges that were removed.
If there are any problems with the above please post the commands that you ran and the full output.