ITunes Match doesn't accept editing of matched music anymore

Question

I am using iTunes Match since one month and everything worked quite well so far.
However, since yesterday I am unable to edit or delete music or playlists that have been matched or uploaded to the cloud by iTunes Match. Every time I try to make changes, they are undone after iTunes Match has been updated the next time. Playlists and music just reappears in the cloud.
In contrast, I am still able to scan newly added music from my library and add them to the cloud or let them get matched by iTunes Match. In conclusion, my influence on my music is reduced to my local data. That seriously has ****** up my library.
Due to the fact that no possible solution i could possibly think of (reinstalling iTunes, login/relog iTunes store/iTunes Match etc.) has worked so far. I contacted Apple's support which couldn't help me also. I talked to three different people for over three hours who also consulted their respective colleagues. No result. They had no clue. Still, they told me they would get advice from the server administrators in the US (I'm from Germany) and would contact me as soon as they had any kind of answer to my dilemma.
Last night I gave it another try and was indeed able to erase my whole online library (I want to start fresh after this disaster) and the changes didn't get erased by iTunes Match. **** Yes! I added an album,waited, updated iTunes Match, erased it afterwards, waited and hoped it would now work as well as it has in the weeks before. Well, that is of course not the case.
Now I have three albums matched. Neither can I erase them from the online library nor can I edit them in any way without iTunes Match replacing my changes afterwards. Adding songs, streaming and downloading music still works fine. I just want to create an well-ordered library for my iOS devices and my computers.
At the moment all devices except one computer (Win 7, newest iTunes) are disconnected from iTunes Match.
Is there someone who might have an idea of how to solve this issue? Thank you in anticipation!

Answer 1

Thank you for your reply, Jim.
In fact I already tried this and it didn't seem to work. For example, I tried to delete a song that had been uploaded to the cloud and waited for some minutes without doing anything. The song just kept staying in the cloud.
In another attempt I left iTunes as it was and did nothing for over an hour. Then I deleted the complete library, waited a few second and closed iTunes. After I reopened iTunes all songs were gone from iTunes Match.
Now I have added and edited some albums to the clean Cloud. The songs that I have edited before I matched them are all correct in the cloud. Unfortunately there are some exceptions. Sometimes iTunes Match automatically scans the library while I'm still editing songnames or albumnames. When I change the tags to the ones I want them to be afterwards everything seems to work but in the cloud the respective songs still have the same tags they had while they got matched. Changes made by me just won't get saved even when I wait for about half an hour before I close iTunes or update iTunes Match. This surely should be enough time for the process of sending and saving of those changes. Some days ago I could easily edit many albums in a row without such problems.