If there is a free item for a main purchase then the terms and conditions typically mean a person has to claim them within eligible dates.
Are you sure Vodafone are offering free earbuds ?
I can see Vodafone UK are doing Trade In deals.
There is also a tech pack that is free as long as it's claimed before a date in December 2021.
Daily Driver > Samsung Galaxy s²² Ultra 256Gb in Phantom Black.
The advice I offer is my own and does not represent Samsung’s position.
I have no affiliation with Samsung.