Deleting addresses from contact list

A person in my contact list has changed email address. I have deleted the old one and added the new. However the old address still appears when I type in the name on a new email.

I also have issues with autofill functions: sometimes an proposal has no link to what I typed and I always have old @ still suggested (even with focus automatically on it).
Is there a way to really remove anĀ  @ from autofill list?