Are you running on LPG or electricity? Whichever it is, try the other. If you are having problems with only one method, you could use the other until you solve the bigger problem. Most people feel that LPG will cool the unit faster. And don't worry until at least 24 hours after you started cooling - the freezer always gets much colder much quicker.
There are many, many posts on this problem and somewhat related ones, like the one I posted just a few days ago.
In any case, it would help anyone trying to give you advice what brand (Norcold)and model # refrigerator you have, whether the problem occurs on LPG or electricity, or both, whether there are any error codes on the refrigerator display panel, and whether you have gone through the troubleshooting steps outlined in your user manual.