What can I do when buyer doesn't pay their invoice but has already received their merchandise?

[CheriByGrace]

What can I do about a buyer who did not pay their invoice but received their merchandise? 

Does PayPal help sellers with nonpaying buyers? 

I hope so. 

Thanks in advance for any help. 

[kernowlass]

@CheriByGrace 

The idea is you don't send anything until you have been paid.

Unfortunately paypal can't force someone to pay you.