Change Selected Text Block Font Attributes

Can someone please direct me how to set the font attributes of a selected text block? I tried accessing the properties through ShapeDisplays but the object always returns nothing.

Thanks in advance!

Sub Main
  Dim MyDiagram As Diagram
  Dim MyModel As Model
  Dim MySubModel As SubModel

  Set MyDiagram = DiagramManager.ActiveDiagram
  Set MyModel = MyDiagram.ActiveModel
  Set MySubModel = MyModel.ActiveSubModel

  For Each MySelObject In MySubModel.SelectedObjects
      If MySelObject.Type = 4 Then ' Text Block

      ' -----------------------------------------
      ' WHAT I WANT TO DO
      ' -----------------------------------------
      ' MySelObject.TextColor = RGB(255, 0, 0)

      ' MySelObject.TextFont.Size = 16
      ' -----------------------------------------

      ' -----------------------------------------
      ' WHAT I TRIED BUT IS FAILING
      ' 
      ' MyObj  is nothing...
      ' -----------------------------------------
      ' Set MyObj = MySubModel.ShapeDisplays.Item(MySelObject.ID)

      ' -----------------------------------------

     End If
   Next MySelObject

End Sub