[2022] Can someone on the Dev-team please explain this to me and refund my lost silver lions?

Hello.

You will not be banned for one instance of teamkilling, but you will always be charged SL for the cost of the aircraft you shot down / damaged.

You can view the team killing policy here:

If you believe you encountered a bug, you can report it here, but please note, the video attached will not be sufficient. A full replay and clog will be required: https://community.gaijin.net/issues/p/warthunder