Unauthorized payments

Good morning I have joined the dating site Jollyme on Friday and took out an 3day trail period of R12. Since yesterday and this morning the website is trying to gain money out of my bank account that keeps declining since the amount that they claim from the bank is less than my present balance in my bank account. I have deactivated and cancelled my account yesterday morning at 4am and they cant seem to be targeting me for funds out of my bank account. Can anyone please assist me in this regard to get them off my back Kind regards Annelise Nagel