Can't get support to answer a simple tech question

I was contracted to develop a solution for a customer using the Everlytic API. I soon encountered an error code 10900 from their servers and no matter what I did, I couldn't get past it so I contacted support via the contact form to ask them what the error means.<br> <br> After a day, they e-mailed requesting more information, which I promptly provided but did not receive a response. A day later I called back about the issue and they promised the person responsible would call me back within 15 minutes