How to prevent a call to the data layer from a mocked object

Question

I have a business object that I am mocking (using Moq) for business tests. When I call the object, it calls another business object which goes to the data layer. I can set a return to calls within the object that I wrote, but how can I prevent it from calling the other object and going into the data layer?

Is there a standard practice for preventing this? Apologies if this isn't clear enough; I will answer any questions as they are asked. Thanks!

Here is an example of the code, simplified just a bit:

Business Test

    Dim mockPer As New Mock(Of IYTDMarketShrink)
    Dim cLogging As New CLogProduction
    Dim cConfig As New cConfiguration
    cConfig.Environment = Ent.MeijerEnvironmentEnum.DEVELOPMENT

    'Create items for use in test
    Dim results As DataTable
    Dim dsTestData As New System.Data.DataSet
    dsTestData.ReadXmlSchema("MarketShrinkPerTestData.xsd")
    dsTestData.ReadXml("MarketShrinkPerTestData.xml") 'Return values for the IYTDMarketShrink data layer


    Dim target As New CMarketShrinkPer(CType(mockPer.Object, IYTDMarketShrink), cLogging, cConfig)

    'Assign parameter values for the mock object
    target.FiscalYear = 2009
    target.FiscalPeriod = 9
    target.ReportType = "CPPTS"

    'Set the return value of the mocked function, call the function
    mockPer.Setup(Function(x As IYTDMarketShrink) x.dsGetPeriodShrinkDetails(target.FiscalYear, target.FiscalPeriod, "C")).Returns(dsTestData)

    results = target.dtGetPeriodShrinks()

    mockPer.Verify(Function(x As IYTDMarketShrink) x.dsGetPeriodShrinkDetails(target.FiscalYear, target.FiscalPeriod, "C"))
    Assert.AreEqual(results.Rows.Count, 9)

The method being called in the business object:

  Public Function dtGetPeriodShrinks() As DataTable
        Try
            GetReportBody()
            Return dtTotalShrink
        Catch ex As Exception
            m_cLogging.LogError(ex, "CMarketShrinkPer.vb: dtGetPeroidShrinks")
            Throw
        End Try
    End Function

And the method in question that is giving me trouble by going to another object, at the bottom of this code (objGeneral.GetInvalidStores()):

Private Sub GetReportBody()
    Dim dsShrinkdetails As DataSet = Nothing
    Dim dvShrink As DataView = Nothing
    Dim drShrink As DataRow = Nothing
    Dim intCurRgn As Int16
    Dim intPrevRgn As Int16
    Dim strRegion As String = String.Empty
    Dim intCount As Integer
    Dim intMarketCount As Integer
    Dim strOrgHcy As String = String.Empty
    Dim strInvalidStores As String = String.Empty
    Dim drNewRow As DataRow = Nothing
    Dim cGeneral As IGeneral = Nothing
    Dim objGeneral As CGeneral = Nothing
    Try
        cGeneral = New cGeneralData(m_cLogging, m_cConfig)
        objGeneral = New CGeneral(cGeneral, m_cLogging)

        If Me.ReportType = m_strCURRENT_PERIOD_SHRINK Then
            dsShrinkdetails = m_cMarketShrink.dsGetPeriodShrinkDetails(Me.FiscalYear, Me.FiscalPeriod, m_strCURRENT_PERIOD)
        ElseIf Me.ReportType = m_strLAST_PERIOD_SHRINK Then
            dsShrinkdetails = m_cMarketShrink.dsGetPeriodShrinkDetails(Me.FiscalYear, Me.FiscalPeriod, m_strLAST_PERIOD)
        ElseIf Me.ReportType = m_strYTD_SHRINK Then
            dsShrinkdetails = m_cMarketShrink.dsGetYTDShrinkDetails(Me.FiscalYear, Me.FiscalPeriod)
        End If
        If Not dsShrinkdetails Is Nothing AndAlso dsShrinkdetails.Tables.Count > 6 Then
            m_dtShrinksales = dsShrinkdetails.Tables(Table.ShrinkSales)
            m_dtStockLoss = dsShrinkdetails.Tables(Table.StockLoss)
            m_dtThrowAways = dsShrinkdetails.Tables(Table.ThrowAways)
            m_dtMarkDowns = dsShrinkdetails.Tables(Table.MarkDowns)
            m_dtGasDriveOff = dsShrinkdetails.Tables(Table.GasDriveOff)
            m_dtCashOverShort = dsShrinkdetails.Tables(Table.CashOverShort)
            m_dtTotalShrinkAmt = dsShrinkdetails.Tables(Table.TotalShrink)
            With objGeneral
                .FiscalYear = Me.FiscalYear
                .FiscalPeriod = Me.FiscalPeriod
            End With
            'To get invalid stores
            strInvalidStores = objGeneral.GetInvalidStores()