You should not sell BTC via paypal in the first place.
Paypal does not allow any swap or exchange of other e-currency in its platform. They are very sensitive about it.
I recommend you to write this off, the odds are stack against you.
I disagree. I've posted this in another thread, but this is relevant: I sell BTC on paypal and ask that the buyer select "personal" and "gift". The buyer cannot chargeback then. Obviously the risk is on the buyer, and this reduces my sales somewhat, but I am focusing on local sales in my home town to establish trust.
I've conducted about 40-50 transactions and haven't had a problem with paypal yet, though i'm not saying it won't happen at some point.