You could start by opening Tracker website:
The contact information displayed here depends on the country you have selected from the upper right corner
This affects also to the instructions given if you would need to send your Tracker gps device to service
There's also a service form you can fill and print out before sending the shipment to Tracker Service / Maintenance
If you would need to contact Tracker Service directly, you can use these:
Tracker Oy / HUOLTO
Kauppiaantie 30
90460 OULUNSALO
FINLAND
Email specifically to Oulunsalo Service / Maintenance:
service-fi@tracker.fi
Email to Tracker Service within Europe:
service-en@tracker.fi
You can also send a ticket to Tracker Service / Maintenance from Tracker website