Go to Hell = Gotogate

I recently used Gotogate.co.za to book a one way flight from George to Cape Town. Not knowing when my business would be finished, I booked a flexible ticket. When the time came to change my flight, I could not find any way to reach them on their website or customer care. The website does not allow for flight changes. And the 24/7 support number keeps on coming back as wrong number. There is no chat bot or even customer care email address I could find. Their website lists them as registered with Amadeus, but I wonder if this is a **** site? I lost a view thousand rand and had to re-book, at a much increased price on the day, via a different more reliable online travel agency. Go to hell = Go to gate