Currently, Tunee does not support modifying invoices that have already been generated. Also, Tunee does not support changes to invoice dates. All billing cycles and invoice generation schedules are fixed based on your subscription type.
Billing occurs on a monthly or yearly basis from the date you subscribed. For example, if you subscribed on the 15th of the month, you will be billed again on the 15th of each following month or year. Invoice dates align with this recurring schedule and cannot be modified.