Bad service

I did call standard bank insurance to ask them to cancel my insurance because I'm having financial problem and if they can refund the amount that were debit the consultant told me some one will call me back in 24hours to cancel, some did call me and the person wanted me to carry on I told the person to cancel the policies and the person just said he will cancel it but he was rude, and then I do get a message stating that I'm must send a cancelation letter to them before 27/06/2024 what must I send a letter if I did speak to 2 people and when the insurance was sold to me I didn't had to send a letter or any documents. If no results will have no other option to seek legal advice because I'm suffering now