Role: Customer
Objective: Let the customer change his current subscription plan.
Reason: The customer would like to change the plan to save his money.
Functional requirements:
The customer can change his subscription plan to one of the two remaining ones.
It is applied based on the selected plan if it is higher or lower than the actual one.
Acceptance criteria:
If it is an upgrade to a higher plan, the change is made immediately, the full amount is charged immediately and the plan is renewed along with new autodebit date.
If it is an upgrade to a lower plan, the change is applied from the next subscription cycle.