Question collection class unexpected behaviour

[verhaba]

Hello
I am a programmer student and for school I am building a small program. I got a collection Class Counters with two members: GetCount and GetCapacity. GetCount is the amount of counters in the collection Counters. GetCapacity is the total amount counters that the collection class can contain. Of course when the max amount is obtained, then should GetCapacity *=2. Now this my code:

Class Counter
    Private m_Value As Integer
    Public ReadOnly Property Value() As Integer
        Get
            Value = m_Value
        End Get
    End Property
    Public Sub Raise()
        m_Value += 1
    End Sub
End Class
Class Counters
    'Geeft weer hoeveel counters in de Collectie counter kunnen zitten. Standaard is dit 16.
    'Indien het aantal counters in de collectie gelijk is de (maximale) hoeveelheid counters in de collectie de wordt _
    'de maximale hoeveelheid verdubbeld.
    Private m_Capacity As Integer
    Public Function GetCapacity() As Integer
        If m_Capacity = m_Count Then
            m_Capacity *= 2
        Else : m_Capacity = 16
        End If
        GetCapacity = m_Capacity
    End Function
    'een indexer voor de counters
    Private m_Items As Counter()
    Default Public ReadOnly Property Item(ByVal index As Integer) As Counter
        Get
            Item = m_Items(index)
        End Get
    End Property
    'geeft het aantal aangemaakte counters weer.
    Private m_Count As Integer
    Public Function GetCount() As Integer
        GetCount = m_Count
    End Function
    'een add procedure om een counter toe te voegen in de collectie Counters
    Public Sub Add(ByRef counter As Counter)
        ReDim Preserve m_Items(GetCount())
        m_Items(GetCount()) = counter
        m_Count += 1
    End Sub
    Public Function GetTotal() As Integer
        For Each item As Counter In m_Items
            GetTotal += item.Value
        Next
    End Function
End Class
Module Module1
    Sub Main()
        Dim counter1 As New Counter
        counter1.Raise()
        Dim counter2 As New Counter
        counter2.Raise()
        counter2.Raise()
        Dim counter3 As New Counter
        counter3.Raise()
        counter3.Raise()
        counter3.Raise()
        '
        Console.WriteLine("De waarde van counter1 is : " & counter1.Value) 'voor indienen, verwijder deze lijn
        Console.WriteLine("De waarde van counter2 is : " & counter2.Value) 'voor indienen, verwijder deze lijn
        Console.WriteLine("De waarde van counter3 is : " & counter3.Value) 'voor indienen, verwijder deze lijn
        '
        '
        Dim counters1 As New Counters
        Console.WriteLine("De waarde van GetCount is : " & counters1.GetCount) 'voor indienen, verwijder deze lijn
        Console.WriteLine("De waarde van GetCapacity is : " & counters1.GetCapacity) 'voor indienen, verwijder deze lijn
        Console.WriteLine(counters1.GetCapacity() = 16) ' GetCapacity() of Capacity
        Console.WriteLine(counters1.GetCount() = 0) ' GetCount() of Count
        Console.WriteLine(counters1.GetTotal() = 0)
        'Console.WriteLine(counters1.Contains(counter1) = False)
        'Console.WriteLine(counters1.IndexOf(counter1) = -1)
        ''
        'counters1.Add(counter1)
        'counters1.Add(counter2)
        'Console.WriteLine(counters1.GetCapacity() = 16) ' GetCapacity() of Capacity
        'Console.WriteLine(counters1.GetCount() = 2) ' GetCount() of Count
        'Console.WriteLine(counters1.GetTotal() = 3) ' counter1.Value + counter2.Value
        'Console.WriteLine(counters1.Contains(counter1) = True)
        'Console.WriteLine(counters1.Contains(counter3) = False)
        'Console.WriteLine(counters1.IndexOf(counter2) = 1)
        'Console.WriteLine(counters1.IndexOf(counter3) = -1)
        'Console.WriteLine(counters1.Item(0) Is counter1)
        'Console.WriteLine(counters1(1) Is counter2)
        ''
        'counters1.TrimToSize()
        'Console.WriteLine(counters1.GetCapacity() = 2) ' GetCapacity() of Capacity
        'Console.WriteLine(counters1.GetCount() = 2) ' GetCount() of Count
        ''
        'counters1.Add(counter3)
        'counters1.Add(counter1)
        'Console.WriteLine(counters1.GetCount() = 4) ' GetCount() of Count
        'Console.WriteLine(counters1.GetTotal() = 7)
        ''
        'counters1.RemoveAll(counter1)
        'Console.WriteLine(counters1.GetCapacity() = 4) ' GetCapacity() of Capacity
        'Console.WriteLine(counters1.GetCount() = 2) ' GetCount() of Count
        'Console.WriteLine(counters1.GetTotal() = 5) ' GetCount() of Count
        'Console.WriteLine(counters1.Contains(counter1) = False)
        ''
        'counters1.RemoveAt(0)
        'Console.WriteLine(counters1.GetCapacity() = 4) ' GetCapacity() of Capacity
        'Console.WriteLine(counters1.GetCount() = 1) ' GetCount() of Count
        'Console.WriteLine(counters1.Contains(counter2) = False)
        '
        Console.ReadLine()
    End Sub
End Module

Who can help? Thx.