I had the misfortune of dealing with them due to being the existing supplier at the property I've moved into. During my initial call (which I had to make due to their website giving opaque error messages), customer service took probably around 40 minutes to pick up the phone, and the advisor was rude and did not understand half of the answers to their own questions. Then after finally switching to a different supplier, they sent a final bill with incorrect estimated meter readings, despite previously having provided the correct ones. I called about this, and once again a rude and ineffective advisor picks up the phone after a long wait time, but at least they promised to correct and resend the bill after much convincing. After 2 weeks, all they managed to do is re-send the same incorrect final bill with the original estimated readings. This time I have emailed them about this hoping for a better result, but I suspect nothing will happen.