Whats happening is that OTE are gradually upgrading all their exchanges to ADSL2. As this happens any provider HOL, Forthnet etc can apply for LLU (local loop unbundling). What this means is they get full access to OTE's wires. The isp well may have their own cables, but the bit from the exchange to your house is 'rented' from OTE. The EETT
are the watchdog over seeing this.
This is the same as happened in the UK 10 or 15 years ago when BT became non state owned.
The situation in Greece is that its a directive from the EU to create a fair competition in the market place. The state have sold some OTE shares but still own a lot. OTE isn't happy about renting its lines to competitors and make it difficult for them. I think by the time OTE do the Crete exchanges things will be smother for you.
If OTE had their way we would all still be using dial-up as they could charge per minute and wanted to keep that kind of revenue earner