Your landing fee at EHGG consists of at least three separate items:
- Landing fees and parking fees. These go to the airport itself.
- Handling fees. These go to the handing agent.
- ATC charges. These go to ATC.
You've paid the first two at EHGG direct. The third one is now invoiced via Eurocontrol.
Here's the link explaining how this works. As others said, as far as Terminal Charges are concerned, Eurocontrol just acts as the debt collector.
https://www.eurocontrol.int/articles...ates-and-ansps
(And I was mistaken in my earlier post. The German ATC provider does NOT use Eurocontrol for Terminal Charges.)