Terrible service from FNB

I recently hired a car through a company called Thriffty car hire. They needed R 6000 as a deposit. When the car was returned after 4 days I got R 5800 +~ back. That was in April 2021. On the 11th May 2021 I discovered R 265 taken from my account from the same company. I called the company up & queried it. They apologized for mistakenly taking out that amount which they ve taken out in April already. Hence the R 5800 return. There was no authorization from myself to FNB to let this company take off this amount. My question is, how can an outside company have access to my private account & FNB says it s because they have my card details. It simply means if anyone has my details then they could take out money from my account. FNB also told me to get a new card!!!! At who s cost???? It s totally unacceptable for this to happen & FNB does not want to own up that there should be more security around someone taking off money from my account. Or anyone else s for that matter.