Undelivered order

I saw an ad on Facebook, contacted them. They gave me a WhatsApp number +27 74 564 3157, we chat on WhatsApp and I gave them my quantities. I paid them a deposit of R4500-00 on Friday with the promise that they are delivering on Saturday. Monday they tell me that my money has not reflected, if I make instant of the balance they should deliver in the afternoon. I made the payment of just over R5600. They sent me an acknowledgement email from order.gemsbricks@gmail.com. They have since been quite and no delivery has been made. I sent them emails and WhatsApp messages, even tried calling. But nothing up to date. It's the 10th day today.