Refund refused

Booked online tickets 24 Jan 2020, one way, for a family of 5 through Gotogate. This was from Wellington to Jhb via Sydney and Dubai. About 5 days later a friend informed me that we may need transit visas for Sydney due to the hours there. On the 31st of Jan I tried calling Gotogate twice and stayed on the line untill my phone cut off. No answer! I also sent Emirates a query on fbm, who informed me that I need to find out from Aus gov. I couldn't get hold of them either. Eventually I got hold of Emirates Aus, and the consultant informed me that no transit visa is required as we will be staying in the transit lounge. This was still on the 31st. I also sent Gotogate an email, with no response to date! When we had to board, we were informed that we could not get on the plane visas are required. I tried calling Gotogate NZ, no answer! Then I phoned Emirates and was told that they can't help me, I need to speak to the agent. Tried calling Gotogates again and still no answer. We then purchased completely new tickets. I managed to get hold of gotogates later during the day, the lady consultant checked our tickets and said we can cancell with a refund and it would take one to two weeks. Unfortunately my phone cut off. I've sent follow up emails to Gotogate NZ since the 11th of Feb with no answer to date. Phoned Gotogates SA on the 18th of Feb and was told that no refund will be made. This is ridiculous! The agent doesn't flag the fact that a visa may be required online. The agent didn't get back to any of our queries sent via email. And I seldom manage to get hold of them via phone. The fact that Emirates Aus informed me that no visa was required is the biggest problem. The fact that we could not board the plane was absolutely not our fault and seeing that we returned back home, the lack of service and information cost us money that should have been spent putting up our new hom. I will never book through gotogate again and only fly Emirates if there is no other alternative.