Glitches in Yahoo Instant Messenger--ignore list?

A person keeps sending me IMs that are verbally abusive. I have blocked him(?) numerous times and he just keeps coming back. When I go to look at my ignore list his name is never on there. I manually add the name to my ignore list but then when I go back and check it, it's not there. The name does stay on my "ignore email" list in my yahoo web mail.

Also I notice that if I clear all the names off my ignore list, the next time I block someone they all just come right back--I cleared my ignore list thinking that the next time I blocked the above-mentioned person, it might work, but it didn't: His name still doesn't appear on the ignore list and all the other names (people I blocked months or even years ago) just come right back. His name is NOT on my contacts list.

What could be going on here? I have submitted multiple "harrassment" reports on this individual and Yahoo customer care just sends me the same form letter telling me how to put someone on ignore!

Thanks for the help!