Tenant makes good faith deposit then backs out Pennsylvania

[Jocelyn Canfield]

Just had a tenant pay a $500 deposit then claim that one of them accepted a job out of state and wants their money back. Of course after receiving the deposit I took it off the market and stopped showing it and turned other people down for the apartment who I had shown it and who were interested. Can't find what the law says about this. I didn't have them sign anything, but made it clear that I wouldn't stop marketing the property until I had their deposit, after which time it was theirs. They made deposit via paypal, so I am guessing they can get it back if I have nothing signed. anyone know what my rights are?