Send it back!
I used to save the junk mail like that from a couple places and after I had a nice stack and they sent me something with a reply envelope I would stuff all their stuff in it and mail it back to them. They get charged more than regualr postage rate for that service so getting a extra heavy package will get their attention pretty quick.
After doing this 2-3 times I no longer get their stuff.
My dad had a VP that would do something similar. They used to get product catalogs from people wanting to see them equipment and often they didn't pay enough postage so they would charge us the postage. It would irritate him that we had to send someone over to the post office to pickup a package and then pay to pick it up only to find it was something we had not ordered. So he would go out to the warehouse and find a bunch of random nuts and bolts and send a package back to the sender, short of the postage, with a nice little note.
I do not, have not, and will not work for AT&T/Comcast/Verizon/Charter or similar sized company.