Open Receivables. Every customer with a balance is in one table, in ageing bands (60 days by default, and you can change them). Filter by All, Overdue, Not due or Promises due, and by sales owner or collection owner.
Click a customer's name to open their account: the follow-up card, promises, tasks, invoices, receipts, the full ledger and a timeline. Record a promise date and amount there.
The buttons on each row call, email, or open your own WhatsApp with a ready message, which you send yourself.
