Indeed, paypal is generally not safe to buy Bitcoin with because of chargebacks.
But, I've been using virwox to exchange Paypal funds for years now without issue, so there are legit services out there.
I suggest you read this first, since you first have to exchange fiat (your PayPal funds) to Linden Dollars, and then from Linden Dollars to Bitcoin:
https://en.bitcoin.it/wiki/VirWoXBeware that they do charge pretty high fees and you'd have to wait 48 hours for your first transfer, after that you can exchange instantly.