GLS does not have to request any kind of returns once they delivered the item.
They can only refuse to deliver it if the personal details do not match to the ID you present.
Once the item is delivered, GLS is out of the process - as it's solely a contract between you and Vodafone. And I doubt Vodafone will ask GLS to collect any kind of item without noticing you first - moreover I doubt that a GLS driver will come up with that request without that you got any kind of information from Vodafone about that return request being sent to you.