Major problem with Contacts

On my mac pro I have a list from iCloud and one from "On my Mac" in Contacts. I have lots of duplicates with names. I spent a lot of time removing the duplicates on iCloud, but they are still listed in "On my Mac". I have removes some of the lists from both groups and they come right back. I have removed deceased people; they come right back. I have worked on this for over 3 hours with no results - still have the dead, the duplicates and the lists I no longer need. Please help. I have 2 iPhones, an iWatch, iMac, and iPad that all sync. I thought if I got it correct in iCloud, they would all be correct. It has not worked.