I have call and ask for a cancellation of my contract on December 2023 and yet that was not done, I was billed every month from Jan to April 2024, which I did the reversal

I have call and ask for a cancellation of my contract on December 2023 and yet that was not done, I was billed every month from Jan to April 2024, which I did the reversal. I was issued summons stating iam owing, and iam black listed, I called 6 x times asking for a copy of my contract which was never sent to me, I would like to understand why iam black listed yet I canceled