Amazon Hasn't Refunded My Money After Sending Me Two Defective Tablets

When I bought a tablet, it came broken, so I asked for a replacement. They sent me another one, but it had the same problems. They gave me a refund instead of replacing it when I asked them to. It's been more than a month, and I still don't have my money back. I sent you an email, but haven't heard back yet. Not only can you not call them, but their chat service is also down. Even though I've sent mail, no one has replied. They tell me to "be patient" and that someone will get in touch with me in 6 hours every time I get an unclear answer. I haven't heard anything in 96 hours. This situation is wrong and has been very hard.