Trouble migrating from PostgreSQL --> Oracle

Good morning,

I've recently just inherited a PostgreSQL database that is a back end
for some logistics software we use here. We have our own Oracle
servers in our group on faster machines with automated backup so we
would like to move all the data over to Oracle.

The software came with scripts to create the owners, tables and
permissions in Oracle but when using "pgAdmin" (Windows client being
used to administer the PostgreSQL database at the moment) export
feature which dumps the entire database in form of insert statements,
seems to not carry over everything we need (lots of data is missing
from the application).

Can anyone recommend a clear cut way to migrate the data over? We're
generating and importing a text file with almost a gig worth of import
statements but we're figuring there has to be a easier way that will
not only bring over all the data but do it more effeciently as well.

Thanks