Hiding default option in a combobox

Question

I have a combobox that pulls a set of options from CRM. The combobox was created in .xaml using the code:

<ComboBox x:Name="cmbTransfer" Width="200" Height="40" BorderBrush="Transparent" BorderThickness="0" Margin="0,0,20,0" AutomationProperties.Name="Transfer State" IsTextSearchEnabled="true" FontSize="20" SelectionChanged="Transfer_Click" IsEnabled="False"/>

In C#, I set the comboboxItem.Content to "Transfer". Then I fill the comboBoxItem.Content with languages to transfer to that are pulled from CRM.

Right now, when I click the transfer dropdown, I get the following: Transfer Dropdown UI

I want the "transfer" in the dropdown menu to not appear. Do you guys have any ideas?

@Sajeetharan: The combobox is populated using the line:

comboBoxItem.Content = (object)current.Attributes["uscb_language"].ToString();

The entity uscb_language is a list of languages from CRM

The action is fired to populate this field with the following method:

        private void Transfer_Click(object sender, System.Windows.Controls.SelectionChangedEventArgs e)
    {
        if (cmbTransfer.SelectedIndex != 0)
        {
            //UpdatePhoneCallActityWithTransferInfo("1233");

            this.FireRequestAction(new RequestActionEventArgs("CTIControl", "FireEvent", "HandleTransfer"));
            //await Task.Delay(20000);
        }
    }