Help Lots of "Unnamed contacts" appearing

[Tom54]

I just met this problem a few days ago on my Galaxy S$. Just after I changed my hotmail-account from MAPI to Microsoft Exchange server.
I can also see that the Unnamed contact (in Dutch: Onbekende naam) is tagged as Micrososft Exchange contact.
But directly going to the webmail on https://outlook.live.com does not show those contacts.
How can I get rid of them?

 

[Tom54]

I got this advice from a Dutch forum and it worked:
https://play.google.com/store/apps/details?id=wolfen.deleteblankcontacts.
I downloaded the app and executed it. All unnamed contacts gone