Changing the email domain for stand-alone Glip (and our individual email addresses)

Hi,

We have pretty much the same issue, except we changed our company name and domain name more than 3 years ago. Everybody in our company has both emails with the previous company domain (eklektik-web.com) and the new one (outsourcify.net), they are used as aliases in Gmail for Business so both work as email addresses.

We use Glip since 5 or 6 years, before it became RingCentral. I had created my account with the old domain name but all our new employees since use the new one. I add them myself in RingCentral Glip right after creating their email address.
Until recently I could choose "add guest as co-worker" for co-workers signed in with a different domain name as mine.

I can't anymore. It seems there was an update lately that removed that option. The issue I have is that I discovered that one of our employees (who since left) mistakenly created a parallel company in Glip with her email address with the new domain name. So now all new users are linked to this other company account on Glip and I can't add them as co-workers.

I don't have access to any "admin portal", we are on the free plan. We are not in the USA so we don't need any of the RingCentral services, just Glip.

The best solution for me here would be if I could change my own email to the new one and in general change our company account to use the new domain name (outsourcify.net) so new users would be linked directly. This is not possible in the app itself. Is there way I can contact some support person to do it for us?
I guess the other parasite company account should be deleted first.

Would be great if we could have a solution here. Thanks!