Reconciling monthly video credits and one-time top-ups with Fincra events

We are evaluating Fincra as a possible payment option for dola ai, a text-to-video and image-to-video service with monthly plans, free daily credits, and a one-time credit-pack option. We have not integrated Fincra.

1. When a customer buys both a monthly subscription and a one-time pack, which Fincra event IDs should we store to grant each credit balance exactly once, even if webhooks are retried?

2. If the subscription renews while a one-time pack still has unused credits, should credit-consumption order and expiration remain entirely in our own ledger?

3. For a failed renewal or a refunded top-up, which Fincra events let us reverse only the affected purchased credits without touching free daily credits or completed video jobs?

Any documentation or sandbox guidance for this mixed recurring-and-one-time setup would be appreciated.