How To: Use a Type definition returned from a function [vb.net]

Please how can I use a Type definition returned from a function?

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Try
            Dim d = Request.Form("payload")

            Dim r = JsonConvert.DeserializeObject(Of request)(d)

            ** this line fails: **
            Dim p = JsonConvert.DeserializeObject(Of DB.ResolveType(r.req_type))(r.data)

            DB.new_request(r.req_type, r.src, r.data)
        Catch ex As Exception

        End Try
    End Sub

The function below compiles, but I get: BC30002 "Type 'DB.ResolveType' is not defined."

Public NotInheritable Class DB
    Public Shared Function ResolveType(type As String) As Type
        Select Case type
            Case "Stop-Action-Request" : Return GetType(cheque_action)
            Case "Cheque-Book-Request" : Return GetType(cheque_book_request)
            Case "Confirm-Action-Request" : Return GetType(cheque_action)
            Case "FX-Transfer-Request" : Return GetType(cheque_action)
            Case "Mobile-Banking-Request" : Return GetType(mobile_banking_request)
            Case "SMS-Alerts-Request" : Return GetType(sms_alert_request)
        End Select

        Return Nothing
    End Function
End Class