This is great, let's hope some folks from DPUK pick up on this as it would be good to have more info on what to do re: red letters and credit rating risks.
I used to work for an gas and leccy company in a call centre, worst job I've ever had as I was answering calls to people getting red letters through their doors, many of whom just couldn't pay and were desperate.
The bit in the video about complaints is spot on, it really wouldn't take that many more complaints than what they're already receiving to overwhelm the system. The call centres are overstretched as it is and staff morale in those places is always low.