Unauthorised debit orders

I recently received a debit order of over a thousand rands from this company, there’s no reference no contract to back up this all of a sudden debit. Nobody is able to explain instead I’ve been waiting for days for one of the consultants to assist. I had closed most of my investments with this *****ed company last year October, it makes no sense at all why money is going out my account 10 months after closing and withdrawing from all investments. This company is completely *****ed and I demand my money back. It’s basically *****