Agreement and evidence assumptions
The rates cover the entire 100 Mbps block. B has $40 of credit available for A. C already has $12 unpaid from an earlier order. A’s budget control shows its remaining purchasing allowance before this order. Admission reserves the maximum for four hours. No payment occurs in this replay.
At first close, assurance has confirmed the unavailable hours at the start and all completed service through 21:00. If the 21:00–22:00 interval could have earned a charge, its evidence arrives in the next period or remains open. A definitive report releases the unused hold or converts it to a charge. A duplicate report refers to the same order, seller and service hour. This model assumes authorised evidence and one ledger. Independent reconciliation by two operators is a proposed trial.