Refund request ignored

We made a booking with the supplier and paid a booking fee of R1500. We also paid an additional amount of R1500. We had to cancel due to unforeseen circumstances and requested that the additional R1500 be refunded. After sending the 1st email on Monday, 18 January 2016, I sent a follow up email and SMS. I am still waiting for a response and expect the funds to be paid to us as requested.