I'm really sorry to hear that you had a negative experience with our support teams. That doesn't sound like a typical situation at all, and I can assure you that if there is an issue with the certificate itself working properly, that is something we would assist you with. If the actual issue is with the installation of the certificate on a third party server, that does limit what support options we would be able to provide.
I would recommend running the tests listed in the following article to determine what issue is preventing the successful installation: https://uk.godaddy.com/help/test-your-ssls-configuration-6015. That should give you the information you need to resolve the error. Thanks.