LCBS Local City Business Search

We received an invoice from Local City Business Search, CP 57546, Montreal Quebec H8N 3A4. Statements on it like *ACCOUNT CLOSED UPON RECETION OF FINAL PAYMENT AS DISCUSSED* If payment is not received by the required payment date, it will be considered a delinquent amount and will be subjet (yes that is how they spelled it) to a late payment charge of 2% per month.
It came with a self addressed envelope for payment. No phone numbers attached but an e-mail address of [email protected]
We have only one person authorized to approve advertising. So we know this was not ordered ever and we have been products of invoicing scams before with a rip off yellow pages company. Hope you can clarify if this is a scam.