Money debited from my account without my authorization

Money was debited in my Account without my authorization by Affinity Funerals on 26/03/20.When I contacted my bank they advised me to contact the company that debited my account.I called Affinity Funerals(Pty)Ltd customer care and spoke to their consultant and she confirmed that there is no record of me purchasing any of their products in their system therefore I am requested to provide an affidavit stating my case in order to be assisted- How do I go about ensuring that my details are removed and debit is cancelled and that an incidence of a similar nature does not occur in the future?***- my contact details ***