Nimble ignoring paid up letter to have my account removed from them

I had a CarTrack account which got settled on 14 November 2025 using the discounted amount then to my surprise in December Nimble sent emails that account is outstanding which I told them it's paid up. Nimble then requested a paid up letter from CarTrack which I sent them together with tha statement but they're still calling sending emails of arrears and that I owe Jan and Feb 2026 but I no longer have an account with CarTrack. I need my details removed from their database and stop being called as I've sent all the things they wanted me to send but now they're quiet when I follow up on when I will stop getting their calls