Phantom car insurance

Good afternoon everyone hope you are all doing well

Sorry to bother but I keep getting mails asking me to send my proof of insurance and I keep sending back mails saying that I sold my car a month ago and thus cancelled my insurance because I didn't have the car anymore yet I keep getting mails that keep threatening to take out insurance on my behalf I don't know who else to contact because as I'm overseas I can't call into a call center to sort this out could you please help me get to the end of this? Thank you