Do you sometimes have to fight fire with fire?

[Bob]

I have a pretty immature ex girlfriend,she is really cute but and can be very nice,but she has no problem dropping people like a hot potato and acting fine. I have already tried talking to her and being nice,and ignoring her,its not getting her attention or phasing her. None of it has worked,even for months she hasn't responded back. My only option left is to fight fire with fire,i mean if she really is like a child,children don't understand how important one person can be,and as a result they forget or replace them,like she is trying to do. So i feel i need to make her jealous and post pictures,and "accidently" send her one or two with me and some other beautiful girls,and maybe change my facebook picture to me and a bunch of friends out having fun at a bar. I also feel i need to "bump" into her looking my best and acting like she doesn't phase me. What do you think?
also don't just say move on,because i still really like her. She's done this to other guys before,but i don't think they've tried what i mentioned. I mean if you flaunt an ice cream cone in front of a child they'll get jealous,same thing applies to her according to what i've said right?