As a woman who literally just had a similar situation happen where a guy wouldn't back the hell off, and even called me "cold" because I told him I wasn't able to date him (I was being nice... He creeped me out and I wanted nothing to do with him), I can 100% say that this is exactly what I wanted him to understand.  OP, please just leave that girl alone.  If she's into you she'll get in touch.  