We no longer issue NPLs, and so will not be able to reactivate your license.
The only two options you have are:
- To purchase a Gamer License: https://www.teamspeak.com/en/features/pricing/
- Or apply for a TeamSpeak sponsorship: Sponsorship | TeamSpeak
Source: TeamSpeak Support
However, the above post is already 2 years old. Last year Chris still meant: