Unauthorized bank charges

Hello. This morning my mother has opened her banking app to see that she is being charged for an account that she wanted downgraded. In July 2023 my mother sent her private banker an email stating that she wants the account downgraded as she does not use the facilities on the account and it was useless to pay for something that she is not using. From August 2023 my mother was not being charged right up until now. I just want someone who can help to reverse those charges as my mother cannot afford to pay for that account hence the reason she requested a downgrade in the first place.