I need help on how to best build a solution
I've been working on a solution that requires to check some data monthly for a prodct that we sold.
For example, if I sell a cell phone plan to company A, I do have to track the payment every month for that company. Now, if I sell 2 plans to company A, then I have to track 2 payments every month.
What would be the best way to track the payments and to be able to tell if that client is late or not?
Any input much appreciated.