Didnt catch the part about scammers...i am talking about the ones need their PSC money into paypal, not reversed.
You cant lock a psc from some countries*
If you have the card you can unlock the card within two days max.
(I unlocked a card by just giving the serial number, they didnt ask for photo of the card, but its better to be in your hands if asked for proofs of ownership)
Anyways...this is the most secure way for transactions, either for income or outgoings. I Suggest that, now its your choice to follow it or not :)