Never send a thing till you get the email from paypal to say it is ok to post.
If you get an echeque you wait till you get the payment has cleared email
All you can do is contact the buyer and ask them to repay a they payment has not gone through and hope they will.
If the email from paypal showed it was ok to post when the payment was received then contact paypal and tell them as they said it was o to post then they need to put that payment into your account now or you will go to the FOS.
