I don't have Audacity, but in Music Bee the bitrate of the HD files comes up at just over 3000 kbps, whereas the flac files from my cd are just under or over 1000. Each album also takes up over 1 gig of space, which is 4-5 times that of most albums in flac format, and about 3 times that of an uncompressed wav file, so I'm pretty sure I got what I paid for (or maybe I should say I got what they said I was getting). In the end it was a cheap way to find out that I don't need to spend a bunch more $. And I have no idea why the sound would be different in the way I reported. Since I can't reliably tell them apart, for all I know it was in my head.
You certainly paid for and received the 24/96kHz box. Whether you got any Hi-Rez files in that box is a different issue.
Audacity is free: http://audacity.sourceforge.net/ There are versions for Windows, MacOS and Linux. It's a lot smaller download than your albums were, too!
I'm no expert in how to use it, perhaps BigShot or Ethan Winer could post a few pointers, but for the purpose of determining whether your files are truly Hi-Rez I can coach you through the steps.
Download, install, and start Audacity. Click past the "Where is Help?" pop up.
From the "File" tab choose "Open..." and navigate to and open one of your Hi-Rez files.
While the song is stopped or paused, from the "Analyze" tab choose "Plot Spectrum..." If a "Too much audio was selected" dialog box pops up just click on "OK." A "Frequency Analysis" window should pop up.
If it's a RedBook file, the frequency plot should go out to 22kHz with meaningful signal out to or very near 20kHz.
If it's a true "recorded at 96kHz" file, the frequency plot should go out to 50kHz with meaningful signal out at least to 40kHz or so.
If it's a RedBook file hiding in a 96kHz box, the frequency plot should go out to 50kHz but meaningful signal will only go out to 22kHz or so and drop off a cliff after that.