Ok, ladies, i need your input on this!?

Ok, my ex is getting on my nerves. Let me start off by saying i'm not over her yet. anyways, 2 months ago, the ***** texed me, i replied back, then her reply again was "who this" so, i ignored it.in fact i was moving on. 2 months later, yesterday, she texed me to ask "what's up' i responded politely with a simple 'hey", then the same stupid reply came again "who this" last time we talked she said she wasn't in a relation. so, im puzzled as to who might be punking me with silly questions.......i have decided to block her. but im confused why shes being weird.