I am sorry to hear that this has happened to you.
Contact Seller PERFORMANCE, not Seller Support. Provide them with the email from the Seller about the listing they want you to remove as well as the information about the negative customer reviews obviously coming from the same. Also make a copy of this for Seller Support. They will be able to verify IP addresses and see that it is the case.
Note: Seller Performance, Seller Support, and Customer Support do not talk to one another. Also, do not tell SS and SP that you sent the message to the other department. If you do they may say “They will get back to you” and wash their hands of it.