Textbox on UserForm doesn't refresh when I change ComboBox2 Value

Question

Here is the code, I have 2 ComboBox's on this form and 2 TextBox's and for some obscure reason when I change the debtor ComboBox it Refreshes the Balance, but doesn't refresh the Price; Price is a cross reference of Debtor and Quantity.

Private Sub UserForm_Initialize()

    Purchase_Select_Debtor.List = Workbooks("New Template.xlsm").Worksheets("Debtor_list").Range("A2:A13").Value
    Purchase_Select_Debtor.ListIndex = 0

    Purchase_Select_Quantity.List = Workbooks("New Template.xlsm").Worksheets("RangeNames").Range("A15:A20").Value
    Purchase_Select_Quantity.ListIndex = 0

End Sub

Private Sub cmdBuy_Purchase_Click()

    Purchase_Select_Debtor.Value = Name
        Purchase_Select_Price.Value = Amount
    Purchase_Select_Balance.Value = Balance

    If Name = "" Then
        MsgBox "Select Debtor"
        Exit Sub
    End If

    DebtorRow = 1
    Do
        TempName = Worksheets("Debtor_list").Range("A" & DebtorRow).Value
        If TempName = Name Then
            DebtorBalance = CSng(Worksheets("Debtor_List").Range("B" & DebtorRow).Value)
            Exit Do
        End If
        DebtorRow = DebtorRow + 1
    Loop Until TempName = ""

    If TempName = "" Then
        MsgBox "Debtor not found"
        Exit Sub
    End If


    Worksheets("Debtor_List").Range("B" & DebtorRow).Value = DebtorBalance - Amount

MsgBox "You have just Purchased " & Amount & " For $" & Amount & vbCrLf & "Your Account Balance is now: " & Balance

End Sub

Private Sub cmdClose_Purchase_Click()
  Unload Me
End Sub


Private Sub Purchase_Select_Debtor_Change()

Purchase_Select_Balance.Value = "$" & Application.VLookup(Purchase_Select_Debtor.Value, Sheets("Debtor_list").Range("A2:B13"), 2, 0)

End Sub

Private Sub Purchase_Select_Quantity_Change()

Purchase_Select_Price.Value = "$" & Application.Index(Sheets("Inventory_list").Range("A1:G13"), Application.Match(Purchase_Select_Debtor.Value, Sheets("Inventory_list").Range("A1:A13"), 0), Application.Match(Purchase_Select_Quantity.Value, Sheets("Inventory_list").Range("A1:G1"), 0))

End Sub