They called, and said they would take me through "security procedures" to make sure they were talking to the account holder, but they never did.

They just said they noticed I'd requested a MAC, and the conversation went as in my post. It ended without me divulging any personal info, except that I had requested a MAC and used it.

I had a couple of TalkTalk salespersons knocking at the door or week or so ago: they started to ask me who my land line account was with and all sorts of other stuff before they even introduced themselves as TalkTalk sales reps. I had to actually ask them who they were and what was this all about. Told them to go in a very impolite manner!

Well, I've gone.

Now on BT as of 15.10.

Change happened without a hitch.

Have decided to retain my trusty Netgear router. It stayed connected but obviously dropped my TT assigned address. I just needed to enter BT Broadband userid in it and it immediately gave me a BT assigned address and DNS.

No change in speed (synch'd at 7616kbps) , but now I can ask BT to remove interleaving and I'll be back to 8192 synch.

So long and thanks for all the fish.

Final update on leaving Talktalk.

Phone and broadband services switched to BT on planned date of 20/10 without a hitch.

Within a couple of days, BT's user help forum moderators had got interleaving removed from my line and I now sync. at the maximum 8128kbps and get throughput up to the maximum IP profile 7150kbps instead of being capped at 6500. My pings have dropped from c. 20-24ms to 10 - 14 ms. Talktalk support had simply refused to do this for me because they couldn't be bothered. (Same line, same equipment at both ends).

In a final throw of Talktalk-ism, they have issued me a final bill that shows a small credit, but four different termination dates. 22nd for the call plan, 23rd for the line rental, 28th for an early termination charge and 29th for Broadband. I am now in discussion with them to agree one date to calculate everything from. (BT's bill starts everything on 20th).

I'm basically glad to be away from TT.