Unless there is a bug bounty-type program in place, I wouldn't expect an email back. You're wasting your time. I've had the same results as you in the past. I don't even report them anymore.
Slightly off-topic, but check out this great email from PayPal today.
Hi JungleCats,
Thank you for your participation in the PayPal Bug Bounty program.
While we continue to review each vulnerability we receive on a case-by-case basis, we have determined that this bug is not eligible for payment based on the fact the website is in the process of being decommissioned and will be shut down in the near future.
Hi JungleCats,
Thank you for your participation in the PayPal Bug Bounty program.
While we continue to review each vulnerability we receive on a case-by-case basis, we have determined that this bug is not eligible for payment based on the fact the website is in the process of being decommissioned and will be shut down in the near future.
Thank you, PayPal Security Team
yawn