My name was added to manuscript as co-author without my consent; how to get it removed?
Yes, it is definitely unprofessional and unethical to include someone as an author when they do not agree to be one.

If you have contacted the corresponding author and asked to have your name removed, and they refuse or ignore the request, all you have left to do is contact the editor.

Simply say that you have come to understand that your name was included as an author on a paper submitted by (corresponding author), that you did not participate in the work, and that you would not like your name associated with the publication.

That's it. No need to make further accusations or statements, that should be enough information for the editor to act. If it's a reputable journal, they'll realize how wrong this all is.