HI and welcome to the site janjan5uk
it sounds like you have been messed around quite abit by ntl
With regards to the letter you recieved today I would not let it rest with ntl, cos their left hand does not know what the right hand is doing most the time. If you need any help with getting this sorted i am sure someone could PM you a contact name for your area, well the area the account relates to.
If you do need a name just post up which area the account was in and I am sure you will get a good contact name
btw - please stay around on the site as there is so much more to it than just the ntl part and we are a nice bunch