Payment Processor Issue | customer filed fraudulent chargeback

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Illustrative scenario prepared by my practice.
For informational purposes only. This is not legal advice. Laws vary by jurisdiction. Consult a qualified attorney for advice specific to your situation.
Hypothetical question

Quick background on my situation — any input appreciated.

customer filed fraudulent chargeback. I've been dealing with this for about 13 months now and the situation isn't improving.

The amount being held/disputed is approximately $18,253. I have tried contacting their legal department 10 times with no resolution.

Do I have a strong case? What should my next steps be?

Illustrative response

Have you tried reaching out to your state's labor board? They sometimes have free resources or mediation services.