It is a bad idea to downgrade to an earlier version as any security issues fixed in later versions would then be unfixed. It is recommended to always run the latest version.
It is unlikely that an upgrade from 3.3.1 To 3.3.2 will ‘mess up’ a site and attempting a downgrade by copying over files from an earlier version than 3.3 may cause more problems than it solves due to database changes in releases. It may work, but downgrading is not supported.
The only way to reliably downgrade after a failed upgrade is to restore the and database backups taken before the upgrade.
It will be preferable to fix the issue on the upgraded site. More information is needed on what version WordPress was at before the upgrade, the PHP version and what the actual issue is. The phrase ‘messed up’ is too general and does not help identify the actual issue, so details of what has happen to the site may help identify the problem and allow a solution to be suggested.