Plan changes with non-expiring creative credit packs: Fincra event mapping

We are assessing whether Fincra could support payments for dreamina ai, an independently operated image-and-video creation platform. It offers free daily credits, paid monthly or yearly plans, and one-time credit packs that do not expire. Fincra is not integrated today.

1. If a customer upgrades a paid plan mid-cycle while still holding an older one-time pack, which Fincra events and transaction references should be used to map the plan change and any prorated charge?

2. Should the order in which daily, subscription, and non-expiring pack credits are consumed stay entirely in our own usage ledger, with Fincra used only as payment source of truth?

3. If the plan payment is refunded or disputed, how should we identify and reverse only the affected subscription entitlement without altering the separate one-time pack?

Pointers to plan-change, refund, and webhook testing documentation would help us design a correct integration.