Problem Blocking Facebook Members From Chat

So here it is,.....blocking specific people from chatting with you on FB is easy.....as is blocking people out right. But not so on the facebook app for the iphone. I've had the app for a while and have found that I can turn OFF chat (there's still people I want to talk to) or block people out right..........those are my options. There's no "block from chat." So while I think it's dumb that they can message me on the app when I prevented them from doing so on the real program...is there a way to block them from chatting with me on the app,...WITHOUT blocking them outright? Jeesh, huh?