Vodapay voucher not received

On 25 May I paid R300 by using a credit card on Vodapay for a R360 Spur voucher. Sadly, I never received the voucher code by SMS or in the Vodapay app. I have reported the issue twice to Vodacom (and followed up too) and was promised that an investigation would be done, but nearly three weeks later I still haven't received any feedback. It doesn't appear like something that would take too long to investigate: where is my payment and why wasn't a voucher issued - it's really simple! Can Vodacom please advise?