I've been defrauded by someone. How do I cancel the transaction. It has not been 24 hours.

[wicjac]

How can I determine if a transaction has been completed? It needs to be canceled. I've been defrauded. 

[kernowlass]

@wicjac 

A pending / processing or sent payment can't be cancelled, you would need to do that via the merchant you purchased from.

As long as you sent the funds using goods/services then you would have buyer protection for non receipt of item OR item received but not as described.