Prezi's apparently trying to cover their posteriors in the wake of Shubham's disclosure and subsequent snub ( http://blog.shubh.am/prezi-bug-bounty/ ).
"We greatly value this feedback."
Weak sauce. Shubham's disclosure saved Prezi from a future nightmare. If they're not going to pay him from the bug bounty coffers, they should at least try and sound more like grateful humans rather than a pissy HR department trying to do damage control.