ANY paypal transaction can be chargeback
maybe , you're right , but once I faced a problem with personal payment . even I called to PayPal support , but they said to me , we can't help you in personal payment , it can't be refunded . that is why I write this above .
Simple. You call and tell PayPal it was an unauthorized transaction or someone hacked into your PayPal account... they will reverse it. Just tell them it wasn't you who made the payment. Or call your bank and file a transaction dispute.
You can charge it back.
Options I can suggest:
1. Withdraw your PayPal funds to your bank account and take that money out of the account and pay for the bitcoins with a non-reversible or less risky payment method.
or
2. Use escrow here with your PayPal payment. The bitcoins are held by a trusted escrow and you send the PayPal funds to whoever wants to sell you some coins. You then wait 180 days until the funds can no longer be chargebacked and then escrow releases the bitcoins to you. (I imagine you don't want this option)
or
3. Find someone willing to take the risk. Or use exchanges which accept PayPal.