Stayed 1 night due to unsanitary rental, promised refund, now collections?

Booked a 12-night short-term rental in Miami with CozySuites. We stayed 1 night and left because the apartment was unsanitary. They couldn’t fix it or move us to anything acceptable.
Their rep told me: if we leave, we’d get a full refund. I have the call recorded and I told him I was recording.
Then nothing. I followed up multiple times. No refund.
Filed a chargeback with my credit card and sent photos of dirty conditions/audio proof/messages. Credit card sided with me.
Now 9 month later, they sent the full 12-night amount to collections. I disputed it. Collector sent “validation,” but even their own docs show the chargeback was decided in favor of the cardholder for “product unacceptable.”
Have you had similar situations? how would you handle this? This incredibly annoying given I have all this proof and yet they’re still trying to collect.

Author: logusya76