You could send multiple emails to her. She might respond afterwards or maybe if you titled the email something that she might respond to like "Payment Options" or something similar.
I have never had that. I do know she does not respond to skype or email messages (unless booking related) and that makes sense as this is her work, but I do love Yona and, to be honest, she is the only reader I use. I am a reader myself and incredibly hard to read for, and the only ones I trust are Yona, and sometimes Mattie from CP - but Yona wins for me hands down