You should leave a freezer which has been transported for about 24 hours before turning it on; then leave it to cool down before putting anything in it.
When operating, the freezer should maintain a temperature of lower than Minus 17 degrees centigrade.
As you have been using it incorrectly I suggest that you empty the freezer and turn it off to defrost it; you should leave it with door open for at least 3 days to fully defrost all the internals before swiching on again
Geoff
December 2010