Here's how to get a refund on the website (all automated):
1. Profile Icon -> Get Help
2. Send us a Message
3. Click 'Refund'
Big corpos only talk money, so it's the best you could do in this situation.
If you can't refund, and need to wait till sub runs out after cancelling, go to the OpenCode repo and rename your tools so they start with capital letters. That'll work around it. They just match on lowercase tool names of standard tools.