I installed Windows Server 2012 R2 Data Centre on a server at work (we're connected via VPN) and it automatically activated. I imagine this is because of a KMS server within the network.
My question is - because I was unaware it was going to automatically activate - is the company going to get billed for the license or is it an already purchased license etc...? I'm not familiar with volume licensing or how the kms systems work?
I'm scared I may have just cost the company thousands unknowingly?
I assume you have Microsoft Volume License. It works that way: company purchases the license for specific amount of OS. It receives from Microsoft the key for KMS. Your company will not be "punished" - you will just purchase extra licenses. To be proactive and control the situation you can use this great tool download from here: Volume Activation Management Tool (VAMT) 2.0
It will scan all your network and report license status for every Microsoft product: OS and Office. Than you may compare the output with your current amount of licenses and make an ajustment.