Hi @mariomouris, welcome here.
I'm sorry to read that you can't login in My Vodafone. I understand that you get an error; 'No user roles are available'. This error means that it's linked to an empty account. When I check your account it isn't merged with Mijn Ziggo.
To resolve this error I removed your My Vodafone account. You can register a new My Vodafone account on this page. Please let me know if you can login after this.