iTunes match is downsampling my library

I am curious to know if anyone else is experiencing this rather unsettling issue with iTunes and iTunes Match.

I have loaded 150GB of music to my MacBookPro directly from CD's I own at 320kbps. To be clear these are all songs from physical discs I own and are not "downloaded" from iTunes store.

The other day on Shuffle mode iTunes played the _censored_ (ie: "clean") version of Cee Lo Green "F*#K You." I do NOT own this version and have never had this "clean" version in my possession. I only have the original "explicit" version from the CD. I called iTunes support to inform them iTunes Match had censored a song from my library and downloaded it to my computer while removing the explicit version. They had no explanation.

I then examined my entire library of songs on my MacBookPro (where the CDs were used to load) and THOUSANDS of songs were no longer at 320kbps but now were at 256kbps. This means iTunes Match "uploaded" my library from the MacBookPro and then"matched" and "downloaded" inferior versions at lower bit rates back ONTO my MacBookPro (replacing most of my 320kbps songs). There are some albums where all songs are now 256, there are some albums where one or two songs remain 320, and there are other albums where all songs remain at 320. There seems to be no rhyme or reason as to why the tracks are downsampled.

This access to my private library and subsequent altering of my library was done without any notification or permission. Apple literally changed data ON my computer without asking.

Having spent over 90 minutes with multiple AppleCare reps... no one had any experience with such an issue and could not offer a reason for the downsampling.

On one level, this is a breach of trust and fraudulent.

On another level, it is a huge frustration that will require re-loading of THOUSANDS of songs.

Has anyone else noticed similar changes with their iTunes music library?

Any help is much appreciated.