"Artists Beware"

I've been a long-time lurker of this community, so I thought I would look for some advice myself over handling a situation in which a commissioner accuses you of being a scammer. 

EDIT: Their DA username is Orchid99 and their email username is suuja93@gmail.com. They seem to have deactivated their DA account a few days ago, and ignore emails when I ask them to send me a screenshot of the supposed paypal transaction reciept. 
 

I've been a long-time lurker of this community, so I thought I would look for some advice myself over handling a situation in which a commissioner accuses you of being a scammer. 

EDIT: Their DA username is Orchid99 and their email username is suuja93@gmail.com. They seem to have deactivated their DA account a few days ago, and ignore emails when I ask them to send me a screenshot of the supposed paypal transaction reciept.