stripe holding $15K for 90 days

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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

Has anyone dealt with something like this? I'm not sure what my options are.

Stripe holding $15K for 90 days. I've been dealing with this for about 15 months now and the situation isn't improving.

The amount being held/disputed is approximately $42,728. I have tried contacting their legal department 6 times with no resolution.

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