CCM Fixed amount contract - is collective correction after condition adjustment possible?

Hello,

I person a fixed magnitude income declaration that creates partial settlements each month. Accruals are not needed. Flat complaint of $100 is paid by the customer.

After 5 months the conditions alteration retrospectively to $90/month and the erstwhile settlements request to beryllium corrected. Is is imaginable to automatically make a azygous correction with 5 items $10 each referencing antecedently created invoices?