DataSource Controls :: Using Dataadapter For Custom Add / Delete Of Database Table

My code is not updating the sql database. I am definately passing the correct information in to this function, and it runs without errors. If I exec the procedure with the passed in data, it works great. Can someone tell me what is missing?

public DataTable UpdateEmailList(int listId, string connectionString, DataTable EmailList)
{
//DataTable dt = new DataTable();
SqlConnection conn = new SqlConnection(connectionString);
conn.Open();
SqlDataAdapter da = new SqlDataAdapter(null, conn);
SqlCommand cmd = null;
//add
cmd = new SqlCommand("dbo.fp_ServiceAwards_AddEmailToList", conn);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add(new SqlParameter("@emailList_id", SqlDbType.Int)).Value = listId;
cmd.Parameters.Add(new SqlParameter("@email_address", SqlDbType.NVarChar, 255, "email_address"));
cmd.Connection = conn;
da.InsertCommand = cmd;
//delete
cmd = new SqlCommand("dbo.fp_ServiceAwards_DeleteEmailFromList", conn);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add(new SqlParameter("@emailList_id", SqlDbType.Int)).Value = listId;
cmd.Parameters.Add(new SqlParameter("@email_address", SqlDbType.NVarChar, 255, "email_address"));
cmd.Connection = conn;
da.DeleteCommand = cmd;
try
{
da.Update(EmailList);
}
catch (Exception ex)
{
string msg = ex.Message;
}
conn.Close();
conn.Dispose();
return EmailList;
}