OVO Energy are also useless

Last year I had mentioned how Foxglove Energy, now named Fischer Energy, failed to bill me for many months; I eventually succeeded in getting a backlog of monthly bills out of them. I am now going through the same with OVO Energy. They used to bill me monthly; I most recently paid them in early June and all the past statements have since vanished from their website. I have poked them a couple of times since; apparently their billing team is investigating. Goodness knows why these corporations cannot manage to simply transform my meter readings into regular bills, I am not asking much of them.

Update: OVO subsequently telephoned to apologize and to cause a retrospective change of tariff that applies a lower rate to my past energy usage.