A dispute is usually an evidence problem rather than a fraud problem. The merchants who win them are the ones who already had the paperwork before the dispute arrived.
In firearms & tactical, disputes cluster around a few specific moments. Knowing which one you are exposed to is most of the fix.
Set rules per item
Enforce destination controls
Structure one environment
Preserve the audit evidence
Card networks monitor dispute and fraud rates at the merchant level and combine them rather than treating them separately. Crossing a threshold brings fees, mandatory remediation, reserve changes or closure — and responsibility sits with the merchant and the acquirer together, which is why a processor asks how you handle disputes before approving you.
Card testing is monitored in its own right, and a merchant can be caught by it without having done anything wrong.
How monitoring programs work