Be Careful - Misleading Wording on "Invoice"

Through some article or white paper I read, I received an invitation from the Institute of Business Publications (IOBP) to review an online publication related to my field of work. The invitation stated that they would send me a couple of issues free of charge, and if I liked them, I could pay for a subscription. The publications were not what I needed, so I waited for the request for a subscription. I got an e-mail saying "This is your last issue under the trial offer; make sure you send a payment so you don't miss out!" or something to that effect. A few weeks later, I got an invoice, worded in such a way to make it seem as if I received goods I was supposed to pay for. It was addressed to my company's Accounts Payable department (we have a procedure in place where the invoice would have to be OK'd by me first, so it did not get blindly paid), and had the following text: "Four issues have already been sent" (in bold type). "Please pay to subscribe for a full year of 34 issues." The wording and the set-up of this "Invoice" is misleading on purpose; they're hoping you panic and pay the invoice, event though it is a trial offer. Very misleading.