I was happy that after a lot of time and tryings I was finally able to register an account in the site,
and I perfectly understand the frustration for that non working captcha,
that's why I wanted to share here my simple workaround hoping it would help someone else.
Obviously, after having tried several different browsers with no positive outcome
and also after trying to follow this other solution which is for my skills a bit too complicate to execute correctly.
In the past I also tried to report the bug, follwing this link Help >> How can I contact a SpamCop representative?
but unfortunately even the reporting form is afflicted by the captcha issue, as you can see
Also, a long time ago I sent an email to report the issue but I after an year I received no answers.
So I really doubt that the captcha will be ever fixed, but since this workaround worked and I finally registered an account I am glad for being of any help.