'We have a tradition at PayPal of supporting hackers'
Yepp, just like you've given the deserved prize to this teen https://news.ycombinator.com/item?id=5779719 when he found a serious bug in your site.
Last 3 or 4 paypal related mails on the full disclosure mailing list also report that paypal is either not responding, not cooperating or weaseling their way out of paying bounties all the time. I'm not sure how seriously I can take this.