Final answer:
To prevent the customer allotment from being affected by the case, use the Do Not Decrement Entitlement Terms action.
Step-by-step explanation:
To ensure that the customer allotment is not affected by the case, you should use the Do Not Decrement Entitlement Terms action.
This action prevents the case from consuming the customer's entitlement allotment.
By using this action, the customer's allotment will remain intact despite the case.