Fort Lauderdale, FL
Here's the Problem...
Not only are you in the wrong review (you are in Wireless, i.e. Cellular broadband, your review should be in AT&T U-VERSE), but you don't seem to realize all companies have systems and those systems are complex and large scale. Canceling right after ordering is asking for trouble since everything needs to be undone. Everything that was in motion, needs to be reversed. Things that come in the mail, were IN TRANSIT while you canceled. Hence why you still received product. Different departments, are not up to date on your cancellation as it takes time. All of this is expected no matter what company you deal with. Don't go complaining because of quick actions you took too soon. I know you felt mislead, but you should ALWAYS ask to see promotions/deals/prices in writing verifying what you setup.
If it ain't broke, don't fix it. Unless you know what you're doing.