Bill cycles, invoicing, disputes, leakage detection and revenue assurance.
3 questions in Telecom.
A cycle closes a period, assembles recurring, usage and one-off charges, applies discounts and tax, then issues an invoice that must never be edited afterwards. A mid-cycle change produces a credit for unused advance rental plus a prorated new charge, which is what customers dispute.
Almost always the money arrived but was never allocated to the invoice that dunning was watching, so an unpaid document aged past a threshold while the account balance was zero. Restore service first, then fix allocation, then make dunning read a state a human can defend.
Restart rather than rerun. The run is not a transaction but a sequence of per-account commitments, so each account must be either fully billed or untouched, charge assembly must be deterministic from inputs frozen at cut-off, and quarantining the offending accounts beats missing the cycle.