I'll keep this short, recently sold a private plate (Retention Certificate), against all advice I sent the certificate in order to get paid. The buyer is now backing out and wants a refund. In my view the scam is they now have the certificate number, which is all they need to assign the registration number. Returning the Certificate is pointless.
I spend several hours last night looking for help, no luck everything is heavily biased toward the buyer. Nothing covers this situation.
Jon.