@ian2 sorry, the internet is a complex place and it can be hard sometimes to find anyone at Company A who has heard of Company B, let alone has any understanding of how they might work from a technical standpoint. So I apologize for the frustration but it’s entirely possible the folks at Globalsign you were working with weren’t familiar with our service or sufficiently familiar with our architecture to comment/ debug.
We partner with Comodo and Digicert to deliver our certificates (not a statement on the value of any other provider) so if you purchase one through us because you want a dedicated SSL cert they are generally equivalent.
You could ask for a refund I suppose… or if they won’t provide one perhaps they have another kind of certificate that might be useful to you that they would be willing to exchange the cert for, such as an email signing cert: https://www.globalsign.com/en/secure-email/
Sorry again for the issues.