Discovery Vitality Unauthorised debit order.

Last year Discovery accepted my application to join Vitality first three months free application. Call centre confirmed, 1st debit in March 2024. 14 Feb 2024 I get a very rude mail stating they cancelled the membership effective 31/12/2023. I phoned them and they informed me as I was a Vitality member before I actually did not qualify for the offer. No problem. I can live without Vitality. Last night 26/2/24 they debit my account (from which they have no authority to debit) with R900.00. I am unable to cancel the debit order from the banking app. I have to go to a branch. Firstly they debit an account with no authority and then they inconvenience you that you have to take time out of your day to go to a bank.