I too suffered intermittent connection problems over the last 3 or so weeks. I contacted them on 25/10, an engineer was booked for a time convenient to me (even down to a specific time with a call from the engineer 15 minutes prior to make sure i was at home). He arrived at exactly the pre-arranged time and was helpful and knowledgeable.
Couldn't fault the service. It does seem that they take customer satisfaction/service very seriously when it comes to their BB customers.