I'm afraid there isn't much that can be done here to help you (this is
actually a FAQ). As there are multiple keyservers that synchronize
with each other, removing a key from one keyserver doesn't really
solve your problem as it can just be re-added from another keyserver.
Even if you could get every keyserver operator to remove the key it
probably wouldn't help you as anyone could re-upload it (some people
upload keys that don't belong to them).