PayPal is run by PCs not humans so more often than not the decisions they make are WRONG!
PayMate is an Australian company run by humans. They actually DO investigate things and rarely stuff up. When they do you can pick up the phone - talk to a real person (Australian as well) and get a satisfactory result.
Western Union should ONLY be used when you know the person you are sending money to. They simply accept cash this end and hand it out at the other - no guarantees, comebacks, promises or claims. ONLY use WU to send money to friends, relatives, lovers etc NEVER for on-line purchases - it is the payment method of choice for scammers as once they have your money it's 'bye-bye' to you.