How do I get rid of 175 messages from the same person?

pattycakes919

The same person has asked for lives 175 times and I can't get rid of the messages.

Lady_Choo

Hi Pattycakes919, does clicking the X on the messages not remove them? 

The trouble is, this is a constant bug bear with no accept all, but they seem to sit in cyberspace sometimes and then come through all in one go which is really annoying.