Synapse Solutions Inc Says I responded to an offer I don't recall Salt Lake City, Utah

I just recently received a notice from Synapse Solutions, Inc., a company that I was unfamiliar with.  They provided no contact information other than a P.O. Box in Utah.  The notice explained that I had responded to an offer for two items, a Wireless Speaker System and a Battery Recharger, costing a total of $52.94, but that I neglected to supply my credit card information; if I wish to receive the items, I need to provide my credit card information or send a check for the full amount.

I do not recall ordering these items, nor do I know where I would have seen them.  It seems strange that Synapse would not have explained from where I saw, and supposedly ordered the items (in a credit card flyer, website, etc.).  They never use the word ordered, they say that I recently responded to an offer.  Only providing a P.O. Box and not a street address also appears curious.

If this company is truly legitimate, they need to include contact information in their notices and explain where these items were seen and where they can be viewed again.  I do not recall these items and I certainly am not going to send payment.