Sky SVBN to O2?

[scot-canu]

So Sky slipped my parents onto the hell of their SVBN, and I only found out now (If I had seen the letter (if it ever came) I would have made sure they were opted out of the change. My parents want their sky package cancelled as they are sick of the rubbish on Sky TV and want to move to a combo of Freesat and Freeview for telly and O2 for BB and phone service, however Sky are suggesting thus far that the line will need to be totally disconnected and they will likely lose their phone number.
However I have seen mentioned elsewhere that someone was able to get their line ownership moved back to BT without losing their line.
I'm wondering if it will be possible somehow for my parents to move to O2 with zero or minimal downtime and without losing their telephone number? Especially since they have relatives overseas and at home who are elderly who use landlines to keep in touch.
TBFH Sky are taking the total and utter p*** IMHO, if they can move it from BT, they should be required to supply a path back or to another provider, rather than hiding behind waffle about "improving customer experience" "doing it for the benefit of the customer" <- in the same way that a dr giving you AIDS would be for your benefit.
f***ing BSKYB

[zee]

Sorry having a blonde momment whats SVBN?

[scot-canu]

Sky Voice and Broadband Network
a Fully unbundled line, which means it costs £45.96 to Openreach to get the line changed so it can be used with other providers again.
As a stop gap they have managed to get Sky to cancel the TV while leaving their BB and phone service intact.

[Undecided adrian]

BT are doing new line provisioning for £30 at the moment I saw recenlty.

Heck they may throw it in for free if you talk a call package with them.

That is the problem with full LLU though as soon as you want to move it's an absolute nightmare and I thought Sky were taking the mic having people opt out of it rather than opt in.