Unable to cast COM object of type 'System.__ComObject' to class type 'ADODB.InternalParameter'. Instances of types that represent COM components cannot be cast to types that do not represent COM compo

I am using ADODB to run a sql strored procedure in VB.Net.

when my code gets to the line

cmd.Parameters.Append(cmd.CreateParameter("CampaignName", ADODB.DataTypeEnum.adVarChar, ADODB.ParameterDirectionEnum.adParamInput, 50, "Annuities"))

I get the error in the title.

Can anybody suggest wy?

sqlstr = "SELECT * FROM WebEnquiries WHERE WebEnquiryID = '" & WebEnquiryID & "'"
        rs.Open(sqlstr, sqlCnn, ADODB.CursorTypeEnum.adOpenStatic, ADODB.LockTypeEnum.adLockOptimistic)

        If rs.RecordCount = 0 Then
            rs.Close()
            Exit Function
        End If


        Dim cmd As New ADODB.Command
        Dim cnn As New ADODB.Connection

        cnn.ConnectionString = sqlDialler
        cnn.Open()

        cmd.ActiveConnection = cnn
        cmd.CommandType = ADODB.CommandTypeEnum.adCmdStoredProc
        cmd.CommandText = "InsertCampaignRecord"

        cmd.Parameters.Append(cmd.CreateParameter("CampaignName", ADODB.DataTypeEnum.adVarChar, ADODB.ParameterDirectionEnum.adParamInput, 50, "Annuities"))
        cmd.Parameters.Append(cmd.CreateParameter("Tel1", ADODB.DataTypeEnum.adVarChar, ADODB.ParameterDirectionEnum.adParamInput, 20, rs.Fields("daytime_telephone").Value))