Unauthorised Debit Order

I checked my statement this morning and realised that there was an attempt to debit R139.95 from my savings account. Capitec informed me that a company called Kianga Trading tried debiting. I called them and they said they cant pick up anything with my ID number and requested my account number which I refused to give. Luckily my salary now gets paid to a sub account and not the savings one otherwise I would have lost money. I want to know what security measures Capitec takes to ensure that our accounts are not manipulated like this. Why don't they verify with us, their customers if indeed we authorised the debit order or better yet compare the signature on the documents with the one they have and see if the instruction is legit? I fear for my money since I will be expected to bring a letter from the company I have never heard of to enable the reversal. It is so unfair. How should I trust you Capitec? I want answers. I wonder how many clients are aware of this....