Hi @RobertsE thanks for your reply.
Ah yes, a couple of customers have thought the same so I do apologise for any confusion caused here. You will be able to use the phone as normal until the switchover is complete! It only blocks calls from that given date, if you've not booked an engineer slot in (as an invite to call us).
It's not possible to get anything earlier to the switchover I'm afraid, all customers are given select slots and generally these are all quite close to the date. The earlier ones are reserved for the customer who are switching over earlier.
I hope this helps.
Many thanks
Tom_W