Journeyblitz errors

I was busy booking a flight using the journey blitz special offer +- 9PM 31 May 2019: 2 adults and 2 infants Johannesburg to Munich departing 9 July 2019 returning 23 July 2019. It had availability for economy outbound flight and business class inbound flight and quoted me R16k taxes and fees. I continued to the point to select seats. When i selected the seats it gave me an error and did not want to continue with the seats and when i returned to re-book the flight there was an error that there is no inbound flight available on Journeyblitz. This is not acceptable as I was busy booking and some error on the website gave me issues. Now today is the last day to book and your call center is closed so I am unable to contact anyone for assistance.