Does GB tech support even exist?

I haven’t seen any reply from them…

GBX staff don’t, as a general rule, post on the forums. Official support for BL3 is through the 2K support desk:

https://support.2k.com/hc/en-us/requests/new?ticket_form_id=360000889214

The support sections in the forums are more for general knowledge support between users, although GBX staff do check them to keep an eye out for new issues.