I am with another provider and have been slammed 6 times within one week by BT and extremely fed up with having to spend half an hour on the phone each day reinstating my account. I rang BT and have been told there is nothing they can do. I cannot understand how this can continually happen with no security checks and also the fact that as my provider has had to re-instate it 5 times already that BT don't realise they may be making a mistake. It's extremely frustrating so any help or suggestions would be appreciated. thanks
Somebody must be placing an order with BT Retail, and giving the wrong address.
Your provider should be notifying you beforehand, that someone is trying to take over your line, and you need to stop it, by contacting your own provider.
This can often happen in blocks of flats or apartments, where the wrong property number is given by the person placing the order.
Its up to your current provider to prevent the line being taken over.
There is nothing BT Retail can do about it. Any provider could do the same, and place an order to take over your line.
See link and sub links regarding what Ofcom say about slamming.
I had a friend with a similar issue - turned out to be somebody in a neighbouring street getting the end of the postcode wrong.