No communication to keep promises made

On 28 November 2019 I purchased an item online from Sportsmans warehouse , As it was a Vitality item I did expect the appropriate refund as I had paid by Discovery Bank Card and the retailer had my Healthygear card number. My HealthyGear card number is ***34 4335. I used my Discovery Bank Card to make the purchase (number ***22 5085). I called Discovery Ref *** who advised me to send a mail. This I did on 30 December 2019 Ref ***. In response Discovery advised that I would receive a response within 3 to 7 working days. On 15 January 2020 I reminded Discovery of their promise and the response was that they would respond within two working days ref ***. As of today, 22 January 2020 I have not been contacted. I had missed calls but no messages and when attempting to call the number I could not reach them. It is not difficult to leave a message or even send a mail should there be no answer.