You have earned rebates you have not claimed. Not because anybody was careless — because the entitlement lives in a manufacturer agreement in a filing cabinet, the volume that earned it lives in the purchase-order ledger, and nobody owns the reconciliation between them.
Every one of the four ways a rebate goes missing looks like nothing at the time. A tier threshold crossed in November and claimed at the October rate. A claim filed three weeks after the window shut.
A designer substituting a fixture that happens to sit off the programme. A distributor settling a rebate earned on your volume into their own account. None of them is worth escalating on its own.
This is the only line in procurement where doing nothing produces no evidence at all. A rebate you did not claim generates no document, so there is nothing for a variance report to find and nothing for an auditor to flag.
You bought the volume and claimed at the lower tier, because nobody totalled the year until after it ended.
The entitlement was real and the paperwork was late. Only the windows still open come back.
A specification change moved a SKU off the programme and nobody priced the entitlement it walked away from.
Earned on your volume, paid to someone in the middle. A contract conversation, not a data problem.
The rest of this model — the data sets it runs on, the cause split, the working behind the reference figure and a sample output — goes out by email. Two fields, nothing else.