Mercari complaint: Mercari protects sellers not buyers

I made several purchases through the Mercari app and even sold a couple of things. The problem happened when I purchased a homemade set of Minnie ears from an Etsy shop who was using the Mercari platform to sell her product. When I received the item, everything seemed fine. I marked the sale as good (you have 3 days), and put the Minnie ears on display in my room. However, within about a week the ears began to fall apart. I reached out to the seller to try to resolve the issue, who proceeded to hide behind Mercari’s 3 day policy and not either give a refund or produce a replacement that wasn’t falling apart ( the glue she had used was not holding). I reached out to both Etsy (because that’s where her shop was from and was referenced on Mercari) and Mercari to inform them of what happened. Etsy immediately responded, of course, they couldn’t reverse a payment that wasn’t made on their platform, but they were taking action to flag the seller. Mercari on the other hand stood by their 3 day policy even though I sent the conversation between the seller and I, provided pictures of the product falling apart, and per their own site could see that the seller was also the manufacturer of the item. Mercari refused to help. I let them know my next step would be to contact my credit company because it is never ok to facilitate taking someone’s money and not providing the product paid for. Mercari responded by saying “good luck talking to your credit card company” Then, after my credit card reviewed what happened, they sided with me, did their job, and protected me, the buyer by reversing the payment. Mercari’s response to this was to shut down my account. They removed everything I had listed to sell. They canceled a purchase that was waiting to ship. I demanded communication, but the summary of the response was “we’re sorry, we’re reviewing” and ended with “your account will not be renewed”. Mercari has treated me terribly. Their responses are generic, no one is asking me questions or trying to understand what happened, and I the customer who was victimized by a fraudulent seller through their sight was the one kicked off.