IP infringement report keeps asking for the same info

IP infringement report keeps requesting identity info

There is a seller who is selling my artwork. I have repeatedly filled out an IP report against them yet I keep receiving this response:

We have looked over the additional information regarding your identity and could not verify the information you have provided. If you believe there was a mistake, please resubmit the notice with any additional information requested and the verification code below.

What information are they looking for? I’ve sent my addresses information and all the required fields. I’ve sent screenshots of the original file and artwork.