ADSL & Moving House/Line Query

[#1]

Hey guys, hope someone can help with this query, as I'm slightly stuck...  With regards to moving the ADSL service along with the telephone line...
I have a telephone Line with "Company A"
I have ADSL service on that line provided by "Company B"
I am moving across the road, ie: from the one side of the road to the other.  My telephone number will stay the same, and its using the same exchange too, along with connected to the same "Green Cabinet" at the end of the road.
Now, if I understand ADSL correctly, the ADSL service is provided at the DSLAM level in the exchange, then routed from the Exchange to the local green cabinet, a panel contains the numbers/circuits which leads onto another panel, to which the 2wires run to the building.......
My guess/understanding is:
If the telephone line is moved, the engineer come to the green cabinet in my street, and just change the connecting cables over so my current number moves over to the house opposite me (which has a teleline already)...
If that's the case, then surely the ADSL service would continue to run as normal when the lines switch over, as nothing would be changed at the Exchange ?
I ask, as the current ISP said I would need to cancel my ADSL with them, and re-order when the new line becomes active (which would be about 2hours after it goes down), and wait 5 days for the ADSL service to come back online ?
surely that cant be the case

[#2]

That should not be the case at all, but you should advise phone company A that there is an ADSL service on the line and to make sure it is not disconnected or cancelled by any action on their part and to make sure that Openreach are aware that they are transferring both services presumable at the Cab.
I would advise Company B that the service should not be disconnected at all, as all that is happening is a change of connection at the Cab to a house across the road, and that company A has been advised that the ADSL service from themselves (B) is present on the line.
If they are incapable of simply changing the address details on your service and insist on "cancelling" then you expect NOT to be charged as cease fee, reconnected again FREE of charge and connected back on your current package all without any penalty.
Any other action on their part will result in you making a complaint to the Regulator and going to the relevant Adjudicator to reclaim any such charges.
However, the fly in the ointment in all this is Openreach who may have other ideas and my guess would be that this hinges on company A providing full details to Openreach.
If company B are being awkward, ask for a MAC within the relevant notice time before the actual move, what ever you do don't cancel (at least not at this time), and see what that does!
This should be straight forward. If company B is Plusnet then just say so, one of the DCT here should be able to resolve this without issue.

[#3]

Cheers for the reply.....
I'll come clean..
I have a plusnet business phone/Broadband line which we use for email (fixed IP), plusnet support said I put in an order to move the lines from our building on this side of the road to the building directly opposite us, easy peasy and they will do it on the day I ask with around 4hrs downtime for the engineer to switch the cables in the Cab, have lunch and drink a cuppa, etc
This part I like...
The line in question is this, I have another teleline managed by Chess Telecom (useless firm), so standard Openreach network, ie: "Company A"
The broadband on that line is provided by Demon Internet, or now known as Vodafone broadband,  ie:  "Company B"
I use this ADSL for our VPN (fixed IP)
Chess Telecom know there is broadband on the line, but only info they give is "when they put the order in to move the line, they give me a ref number, which I need to give to Demon Internet, to tie in the order of moving a line and broadband".
Speaking to Demon, they say I just need to cancel my broadband and reorder it which can take 5 to 10 work days 
Hence I wondered about the whole line move done at Cabinet level.  Apologies for not being PlusNet related, Chess or Demon don't employ technical people or anyone whose able to answer simple questions

[#4]

Ask Demon why they don't use simultaneous provide codes!

[#5]

That's it in a nutshell jelv.
I've had a further thought on this, is there an active phone line over in the new house? Because if so, Openreach may well consider making the change at the exchange. Now that could mess things up - it shouldn't, but it might. Personally I don't see why the Circuit ID's should change, the phone number won't,  just the exchange records will change. But the line quality may change - what is the quality like at the moment?
I think I'd make a call to OFCOM and ask for someone with the technical knowledge to explain what the procedure should be (not an ill-informed adviser making guesses).
I would be inclined to ask Demon 1) Why don't they seem to be following recognised procedures if your phone supplier is giving the relevant reference number especially for them to use, presumably with Openreach.  2) Why don't they speak to Openreach and double check on why this shouldn't be straight forward    3) If they are choosing to go down the route of cancel and re-order are they proposing to charge you anything for this?
4) What about the 5 days of lost service?
What if anything is so special about this Demon service, isn't there as good or better a deal available with another provider.
I'm thinking, if push comes to shove, if there's an alternative provider with a suitable package, ask them how quickly they could transfer you with a MAC and then explain the house move to across the road. The problem I possibly see is if Openreach/BTw go changing circuit ID's.