It's a frightening feeling to not feel in control of bills etc. I just discovered my electricity provider hasn't been producing bills since last Dec - 6 months! Despite getting readings. It happened last year to thousands of customers who got suddenly landed with massive bills. Although I have a smart meter it doesn't connect to a good signal, so data wasn't transmitted and I had to change tariff last year. This may have been the reason for bills not be produced. To add insult to injury, I don't even have the meter on my flat and have to wait for readings to be given. So have been freaking out about this. The approach you have is correct.