Then, i cant generate a new invoice with the total pending amount of previous invoices fron the same customer, plus the current amount of this new que invoice?
Example:
February invoice amount 30
March amount 40 of 100
Then. In April generate a invoice for 100 plus pending amount 70 ( 30 of march, and 40 of april), total payment 170.
If customers pay 170 then three invoices payed, if customer que only pays 70 then oldest one must completed and left one invoice for be payed in a next payment