Paperwork and public services
EETT (Hellenic Telecommunications and Post Commission)
In short
The independent authority that oversees phone, internet and postal companies.
EETT is the national regulatory authority for electronic communications and postal services. It regulates and supervises these markets, and it also acts as the competition authority in them.
If you have a problem with a mobile, landline, internet or postal provider, you can file a complaint with EETT online. Example: you are charged an early-termination fee you think is wrong. Keep the contract and the bill and attach them to the complaint.
Official source: EETT