Referral traffic from my-seo-promotion-service.com is harmful to your site! When you attempt to
Google explain's here just how important "PageRank is Google’s opinion of the importance of a page based on the incoming links from other sites" and goes on later to say "a link from a site is regarded as a vote for the quality of your site".
Traditionally there are a few ways to remove back links to your site.
1. Contact webmaster of the site and ask them to kindly remove the link.
2. Use the Disavow Tool from Google!
What is the Google: Disavow Links Tool. Google's link disavowal tool allows publishers to tell Google that they don't want certain links from external sites to be considered as part of Google's system of counting links to rank web sites. Read more about it here.
Now you can rest easy knowing that websites like my-seo-promotion-service.com can not ruin your page ranking anymore.
The next step you can take to help the internet community, report spam activity! You can report websites that are exhibiting spamming towards you at https://www.google.com/webmasters/tools/spamreport. Reporting spamming site to Google will allow Google to do their own audit on the website and determine just how helpful or harmful the website really is.