Customer satisfaction is a very hard thing to measure.
For instance satisfaction with customer and technical services contact is usually measured by whether a customer with a problem calls back about the same problem. If they don't call back it is presumed that the initial call solved the customers problem and the customer is satisfied. This, however, relies on the agent who took the initial call making notes about the problem on the system. The customer may have found a solution to their problem from other sources (on CableForum for instance) though, particularly if the initial contact has left much to be desired.
My own experience of NTL customer service has been very good with any call which required an engineer visit resulting in a visit the same day, usually within four to six hours, sometimes quicker. Excellent service from NTL at Nottingham. The only problem though was that those engineer visits did not solve the issues with my DTV service. The answer in the end was quite simple, move to Sky+ which has been perfect and streets ahead of NTL DTV.