When switching from a lower level to a subscription at a higher level, the customer’s prorated “unused” amount from the prior in-app purchase is refunded to the original payment method.
The current plan will cease and the new in-app purchase is charged and goes into effect immediately at the full price, which changes the customer’s renewal date to the upgrade date.
There will be no refund when a customer switches from a subscription at a higher level to a subscription at a lower level. The downgraded plan will take effect after the end of the current billing period. Customers will be billed the new rate on their next renewal date.