Unable to block debit order and provide outcome letter

I signd up for SUNO Inc some time ago and over the last 2 months I cancelled the subscription on their website. I only have free subscription now not a paid one any longer. SUNO Inc has been trying to debit my account ever since and when I asked Capitec Bank to return a successful debit order, it did not happen nor did they block the unauthorised and ******* debit order. Capitec Bank claims that they need a cancellation letter sent to SUNO Inc. These AI businesses do not work on emails nor on cancellation letters and you cancel online which Capitec Bank refuse to accept and I am sitting around 15 unsuccessful debit orders as Capitec Bank is unable to block subscriptions and I am left with a bad reputation and monetary loss for unpaid debit order funds. I am not changing my bank account or getting a new card as the bank should be able to block these debit orders as per the Reserve Bank.

I have asked Capitec Bank for their outcome letter a few weeks ago as I am proceeding to NFOSA but they refuse to give me the letter.