Soldato
Order a new service with whichever ISP you want, on whichever access network is an option for you - in your case this would likely be SOGEA but delivered on a second copper pair. For me it was FTTP with an altnet.
Once your new service is in and working, port your current landline number to a VoIP provider. This will notify your current provider who will give you the "sorry you're leaving" notification and let you know when the service is due to cease. When your number port completes the old phone line will go dead, and billing for line rental and broadband will stop.
Superb, thanks @Caged. I suppose my homework is digging into providers who let you move from SOGEA FTTC to FTTP mid-contract. Though if FTTP is replacing all the copper services, I presume that's a given so most provides would let you move?