Unable to register/claim TTIG

I purchased a Browan LoRaWAN Gateway (TTIG) over eBay one year ago. It sat around for a year and I recently decided I’d take the time to get it online. But to my dissatisfaction as I went to ‘claim’ this gateway, eUI=58A0CBFFFE803937, I am getting the message that this gateway already exists and is not authorized for claiming. I’ve already messaged the original seller, but they have not replied.

{
  "code": 9,
  "message": "error:pkg/deviceclaimingserver/gateways:gateway_not_authorized (gateway with EUI `58A0CBFFFE803937` already exists and is not authorized for claiming)",
  "details": [
    {
      "@type": "type.googleapis.com/ttn.lorawan.v3.ErrorDetails",
      "namespace": "pkg/deviceclaimingserver/gateways",
      "name": "gateway_not_authorized",
      "message_format": "gateway with EUI `{gateway_eui}` already exists and is not authorized for claiming",
      "attributes": {
        "gateway_eui": "58A0CBFFFE803937"
      },
      "correlation_id": "3442e5cad5b146f783b4ea850314eac4",
      "code": 9
    }
  ]
}

What course of action can be taken to claim this Gateway?

Thanks
Mike

First, erase the combination of register and TTIG from your mind - there is no way to register a TTIG on TTN, you can only claim it. If you try to register, you will make the situation worse. There is no concept of un-registering a TTIG, do not ask them to do that, nor ask them to just delete it.

Second, format your code/log/JSON with the </> tool whilst waiting for a response from the vendor.

Then search the forum and read the numerous posts exactly along this line which will be something like “ask the vendor to unclaim it, if not, submit proof of ownership to TTI paid support to see if they will give you a Hail Mary”.