Simcard cancellation

I Sent an email to Supersonic on the 1st of March requesting them to cancel my simcard since it was a month to month. When i signed up they had said I must give 30 days notice. I did not get any response from them. I made several telephone calls and sent several emails, but no response on emails, When I call the I get a response that we have escalated your query, you will get a phone call, Up until now, 25 May 2021, no response. I even twitted them I receive the same response we will make a follow up. I am tired, please cancel that simcard, I am no longer interest, I gave them enough notice.