6 iCloud duplicate contacts groups

I’ve disconnected from iCloud, it has never worked for me. Now iCloud had duplicated itself numerous times in addition to duplicating groups within each iCloud group:

Howcan I fix this easily and remove the duplicate iCloud groups? I tried using the duplicate removal tool but only got “The operation has failed” dialog.

I guess from now on it is iTunes syncing over USB. This started when I tried unsuccessfully to log into iClod from an external disk plugged into my Mac. It just seems like iCloud is nothing but a headache.