Recurring-bill double-pay audit after due-date editsSubscriptions & Billing

Task prompt

CX escalated a member who got double-charged for rent after moving her bill due date — the exact scenario Engineering documented on the Confluence page about editing bill due dates and the pitfalls that creates. Start there so you're using the same definitions the team does: editing a recurring bill's schedule can spawn a second money-moving payment within the same billing cycle. Please audit the full recurring-bill book from the warehouse. A payment only counts as money-moving if it actually moved (or will move) money and was never canceled: status completed, processed, or pending, and canceled_at is null in every one of those cases, not just some of them. Per bill, detect consecutive payment pairs whose due_dates fall within the same billing cycle — gap less than half the bill's nominal frequency interval (weekly 7, every_other_week 14, semi_monthly 15, monthly 30, every_other_month 60, quarterly 91, semi_yearly 182, yearly 365 days). Sum the later payment's amount as duplicated exposure, and separately report how many of the flagged pairs are actually linked to a due-date edit on either payment, not just pairs that happen to land close together on their own. When you've got it: open a Slack channel called "recurring-bill-double-pay-audit", post a summary there with the headline numbers and the edit-linked pair count and pin it; file a Bank Operations ticket titled "Recurring bill double-pay audit — due-date edit collisions" capturing the exposure book; and reply to me with double_pay_pairs, bills_affected, accounts_affected, dup_exposure_usd, and edit_linked_pairs.