I'm not sure they have been removing it - but they have certainly been collating it. Every time I reported fresh spam to SpamCop ntl's name came up on the list that would get a message as "intermediary interested in the handling of spam" - so I presume that they have been teaching their spam filters what to look for....
....and then setting it to random
All the above is correct the spam filters have been running for some time at a low filtering setting for the spam server to recognise known or suspected spam the level of spam detection has now been raised.
Legitimate e.mails should not be getting deleted I would advise everyone for now to do as homealone has suggested in selecting the setting of the Spam filter to 'send to webmail spam folder for 7 days' .
Anyone who believes a legit e.mail has been deleted as spam contact tech support the more evidence there is the better.
I know this is not ideal and I am not defending the way NTL has actioned this in anyway.
It would have been better if a warning was given a week before the filtering was increased and set the option to not delete for 7 days as the default,the powers that be have been made aware of a possible issue.