According to an information we received from a friend of iGuRu.gr his network Internet but also Vodafone's 1399, 13830, 13840 phones are not working. 
Phones send the following message: The number you called does not work temporarily for technical reasons.
Also the official one by clicking here the company's https://www.vodafone.gr/ does not work and there is currently no official information.
In case you have too problems connection leave us a comment.
We thank our friend George Kanellakis for the immediate and valid information.
Update 1: The company page returned with the following message
Update 2: The company informed (finally) its customers. The situation, however, seems unique…
But since it was planned downtime they should inform their customers.
Vodafone announcement at Facebook:
We would like to inform you that due to the simultaneous cutting of fiber optics in 3 different routes (Bulgaria, Turkey, Slovenia-Croatia), we encountered a problem with fixed and mobile internet services.
The required technical work was done immediately and the problem is gradually being remedied. We apologize for the inconvenience.
We inform you that due to simultaneous cutting of optical fiber in 3 different routes (Bulgaria, Turkey,…
Posted by Vodafone Greece on Wednesday, September 30, 2020
Lol of Kara-Lol…
Voda announcement:
"We would like to inform you that due to the simultaneous cutting of optical fiber in 3 different routes (Bulgaria, Turkey, Slovenia-Croatia), we encountered a problem in fixed and mobile internet services. The required technical work was done immediately and the problem is gradually being remedied. We apologize for the inconvenience. "
The fact that 3 routes were cut, how to translate?
Were 3 optical fibers cut to the 3 mentioned countries?
Was a fiber cut going to the three countries?
Whatever it was, there was no connecting fiber to Italy?
And if 1 or 3 fibers were cut, the backbone was cut to and from the outside.
But why did internal trafficking disappear? In the final analysis, where are the main servers of the company, of the Greece Sector, located? Greece or out there…?
Nothing works guys… from a desktop computer constantly pulls out the above image
At the moment, Vodafone's fixed Internet totally down is not affected