A few years ago when I worked for ntl, there was a big problem with customer disconnections and direct debits. The real problem was down to the company keeping bad debt customers and disconnected customers on the books to masage the figures to fool the shareholders.
That was the reason so many customers were being charged via direct debit for services after they had left as a customer, I had the problem myself after leaving as an employee with a service I had terminated about 12 months previously. The issue of charging customers in this manner was well known in some circles of ntl, and at least one employee in a management position on the company owned forum was fully aware of the situation.
The act of being ripped off and the problems associated with getting it sorted, along with a debt collection agency after me for £15 was my prompt to get off my backside and find an alternative supplier. I thought it rather a cheek when they in fact owed me over £100