Oct 27, 2015 08:09 AM|seamus1982|LINK
If any one else has the same problem, it is that the name of the parameter is not included in the post request. So the request is like below.
var promise = $http.post(webApiUrls.hostUrl + 'ClientDepartments/SaveDepartment', department)
Just don't add the name of the parameter in the method.