iPad and iPhone - syncing Contacts unexpectedly?

I'm helping a friend with her iPhone and iPad - she wants to rebuild her small contact list from scratch. Both devices have the same account name/password.

So, I have deleted all contacts and turned off Contacts on "Saved to icloud" from both devices. I have also deleted the backups for both devices.

Howevever, when I turn "Saved to icloud" back on, the devices start downloading contacts again - where the **** could these contacts be coming from? She also has an old tired Mac - I went into the contacts there and there were 60,000 entries, many of which were duplicated. I deleted all of them (the Mac almost had a fit!).

Still, the ipad and iphone are syncing contacts again from somewhere......

Any ideas - I am obviously not a great ios expert........