While it is pretty common for heating (as it is mostly centralized either in the building complex or even city district and you stuck with it), it is very uncommon for electricity.

There is something called the “Grundtarif” of the local electricity provider that it just defaults to, but you are not forced to keep it.
This might very likely be it.

You could just try to look up your meter ID and try to switch to a different provider (can really easily be done online).
If you are actually in the Grundtarif, I would really recommend that, as the Grundtarif usually is the most expensive option you can get, so you could save a lot of money.