Guest house booking overpayment by guest ****

I was contacted by a lady called Nosi, who need accommodation for 2 drivers. I sent Pro-forma Invoice with business banking details, only to be told an OVERPAYMENT of R2000.00 had been made. Since this **** has previously been attempted, I was immediately on the alert and said NO REFUNDS unless the funds deposited had been cleared by the bank. The POP and SMS to confirm the payment was sent to me after banking hours. I could however confirm my self that the funds had not cleared in our bank. I called my closest Guesthouse neighbour, same person, same number (+***6) same ****! Needless to say no guest have arrived.