As they are ending up in the spam folder it would appear that the spam filters are doing their job by placing them in the folder rather than letting them get into your Inbox albeit the filter could be better by stopping them prior to getting to your account.
You are wasting your time trying to block them. The email addresses will be spoofed so as to hide the true sending email address.
You could try setting up a "Rule" to discard the emails containing something in the title or name or subject but beware not to use something that a genuine email could contain.
The spam filters should eventually catch up and stop them getting to your account although this can take some time.
