I have now moved home and despite numerous requests to Talk Talk, I have had to go to BT for a 3 month contract and return to Talk Talk after that time otherwise incur the £70 cancellation fee. I rang Talk Talk several times to cancel my existing phone line and was told a different version every time I got through depending on who I spoke to. I was told there was a special department which deals with moving home and ended up being put on hold and then getting through to Customer Services again. The first person obviously did not want to deal with it. I ended up having my outgoing calls barred on the Saturday before I was moving on the Monday (they told me to call bar outgoing calls just in case they didn't cut off my line in time). BT on the other hand were very efficient and my new phone line was activated in the property I was moving to on the day and at the time I requested.
Ofcom could not really help as in Talk Talk's terms and conditions, it says there has to be an active phone line in the property you are moving to (and of course everyone cuts off their phone as they leave don't they!).
Although Talk Talk's telephone and broadband package is cheap, I cannot believe the stress it has added to moving home trying to sort out the phones. Incidentally i am now without broadband at home for the next 3 months while I am with BT. I am not prepared to pay the £18 to buy myself out of the BT contract.
I have written a letter of complaint to Talk Talk, but did not get a response.