is it reportable for not playing support
Like, you are a support. yet you ks( intent) all the kills and refuse to ward or help anything? 
Like, you are a support. yet you ks( intent) all the kills and refuse to ward or help anything? 
Zyra doesn't have a great deal of control of KSing. Her plants can do a lot of work and you can't just "call them off".
However, if your Support is helping your team win, even of you don't like their method, it is not something you can report. Support isn't just the ADC's tag-along, nor are they simply ward whores.
Gotta give more reasons than that.
Unsportsmanlike? Negative attitude? Not communicating?
If you feel this person wasn't communicating their strategy to the team, that can be a reportable offense. But playing sub-optimally is okay, so long as you're earnestly trying to win.