iCloud storing songs as ineligible

I'm using Apple Music's latest version 1.0.1.37. Last week I had 2 tracks that I couldn't play on Apple Music on my Mac. Both tracks were listed as Ineligible and their location was listed as 'Cloud'. Originally, both of these tracks were burnt mp3's and originally located in my iTunes Media folder. I could neither play, re-download or delete these tracks. I contacted Apple Support who suggested 'Since you are unable to delete the song, I suggest you to try deleting and uploading the song using a different device.' I located the songs on my iPhone and managed to delete them. Having the original mp3s saved elsewhere I was able to re-add them to Apple Music and they synced back with iCloud. Yesterday I discovered I had another 16 additional songs listed as Ineligible, location=Cloud and no matter what device I access I cannot do anything with these songs e.g. cannot play, delete etc. All of these songs were previously mp3s on my iTunes Media Folder. and they have been removed (not by me!!). However, what's puzzling me the most is that all of the affected songs are ones that I streamed on my iPhone at various times during the week and now they're all removed from my Media Folder and listed as Ineligible and stuck in the Cloud. Anyone else come across this problem?