Have you ever encountered 2118801700? Readers of iGuRu.gr will know that my relations with Wind are not the best. So you could say that I am biased by reading the following article, but honestly I don't care. I feel something when I am faced with such behaviors...
Are you also one of the "lucky" ones who received one or more calls from 2118801700 for some fantastic offer, or even better for some unanswered call? You are not alone.
For some time now, the same phone number seems to have gone viral on various complaint pages circulating on the internet.
For example, the comments on white-pages.gr about this specific number are revealing:
“They call, albeit on a mobile phone, during quiet hours. (01/02/2017)”
“It is the company plegmanet that collaborates with wind. They are obliged not to call numbers that are included in the article 11 registry but they never abide by the law because obviously the profit is above. Ask your provider to include your number in the registry and remove it from the telephone directories (not that it will have any effect…). Also, call the company directly 2118801700 or 2111051700 and ask them explicitly not to bother you again. Not politely, they don’t understand… you have to swear, threaten with a complaint and lawsuit and persistently ask for information about the company and the owner in order for them to get upset and take you seriously because otherwise they will write to you. (10/12/2016)”
From the dates the comments were posted, you can understand that the promotion company's behavior is timeless, regardless of the complaints they receive, directly through the numbers they use to annoy people, or indirectly through complaints to Wind itself:
Is there any proof that this number is directly related to Wind? Of course… The company itself admits it (we use a screenshot so they don't delete the comment):
How do we know that plegmanet is a subsidiary of Wind (2)? But they don't hide it:
But let's go to Plegmanet, which although has complete data that reveals its physical location, on the internet it seems to have a very ghostly presence. The company's website has been hacked for a long time and no one cares: 
The image above explains why if you try to visit the website you cannot read the Greek characters: It is encoded in UTF-7, instead of UTF-8. Also, the meta of the page has been changed by the hacker:
Hacked By Anonymous Ghost Gaza
As for the customer's right now that the title mentions. Don't look for it, you won't find it, especially if you are polite to such companies. There are dozens of publications starting from 2012 and concerning complaints that remained complaints.
The only way that may help is to submit your complaint through the website of the Personal Data Protection Authority from the link below:
https://www.dpa.gr/portal/page?_pageid=33,24054&_dad=portal&_schema=PORTAL
You can also contact the National Telecommunications and Postal Commission (EETT). EETT is an Independent Administrative Authority, it is the National Regulator that regulates, supervises and controls: (a) the electronic communications market, in which fixed and mobile telephony, wireless communications and internet companies operate
and
(b) the postal market, in which postal and courier service providers operate. In addition, EETT exercises the responsibilities of a competition commission in these markets.
You can submit any fraud report at the link below:
https://www.eett.gr/opencms/opencms/EETT/Consumer/complaints.html
