Customer that try to blackmail you
How to Manage Review Blackmail?
Chargebacks Explained - What is a Chargeback and Why
If a customer threatens to leave a negative review unless they receive some sort of benefit that they are not entitled to, then this is blackmail. ... But beware: threatening to report the reviewer to the police can itself constitute blackmail. If you intend to make a police report, just do it, don't threaten it.
What are customer chargebacks?
A chargeback is a charge that is returned to a payment card after a customer successfully disputes an item on their account statement or transactions report. A chargeback may occur on debit cards (and the underlying bank account) or on credit cards. Chargebacks can be granted to a cardholder for a variety of reasons.