Thank you for your question. While, unfortunately, I am the only active European Law expert on the website, and there can be no attorney-client relationship formed over JustAnswer, I have two options for your case:
1. You can find an English-speaking attorney list for Greece here (https://gr.usembassy.gov/u-s-citizen-services/local-resources-of-u-s-citizens/attorneys/). Direct link to the PDF list here (https://gr.usembassy.gov/wp-content/uploads/sites/206/2017/07/AttorneyList_July2017.pdf).
2. As it happens, I did have cases in Greece, which I dealt with via a very professional English-speaking attorney, who charged me less than the big houses. I could give you his details, but cannot do so except in the "Premium Service form". If interested, I will set it up for the lowest available sum, which I believe is USD 5,-, and send you the details.
I hope my answer was useful. Please let me know if interested in the lawyer known by me, and otherwise please rate the question, which is essential to my activity.
Dr I L Vlad