No voucher no internet

So I'm having a problem buying a 28 day voucher for my fiber connection and apparently the only way to do that is via the portal online. Been trying since yesterday 19/12/19 @ 12:00pm. Contacted them at 12:22 via WhatsApp as as of now still not sorted (20/12/19 16:35). Then I tried to call this number ***3 @ 16:35 (business hours 8 am- 5pm). Automated system answers telling the business hours but doesn't put you through, just says have a nice day.