First, Do not use the "-" button -- it does not disconnect your configurations, it deletes them. (A configuration is a file or files that contain instructions that Tunnelblick uses to connect a VPN, that is, to turn the VPN on.)
"Disconnect" does not mean "delete" or "remove", it means "turn off the VPN". In Tunnelblick, there is a "Disconnect" button, and there are "Disconnect…" menu items. They turn off the VPN.
Second, Tunnelblick is just the software that you are using to connect to a VPN. The VPN itself is run by a "VPN service provider". They are the ones that supply configurations. We only supply the software. (It's sort of like how Safari is the software that you can use to access
google.com: Apple provides you with Safari, but Google provides the
google.com website. In this analogy, we provide software like Apple and your VPN service provider provides a service (VPN) like Google. Not that Google provides VPN, as far as I know they don't.)
You need to contact your VPN service provider. That is the organization which gave you your configuration files, and perhaps a username and password, and to which you are probably paying a fee for VPN service. For more information, please see
Getting VPN Service.
Tunnelblick is just the free software that many VPN service providers recommend or supply to their customers. We do not provide VPN service, just software.
If you can't figure out who your VPN service provider is, please post the diagnostic info obtained by following the instructions at
Read Before You Post. When it says in step 3 to select a configuration, please select one that is still working if that's possible.