Clients have reported getting a bill from "DNS Services", this is not a bill but really a solicitation for business. Do not pay this bill, it's merely a scam.
Here is a copy of the bill to reference:
If you read the highlighted section it explains that they are just solicitating you for business by trying to scam you into thinking you owe a bill.
I suggest you simply throw the bill away, do not try to contact them as that will confirm the contact information they have for you is good and could lead to further spam or misleading mail.