PURCHASE MADE FROM MY ACCOUNT WITHOUT MY KNOWLEDGE

This morning I got a bank notification R1172.85 was taken from my account, it states that I made an ad purchase of which I don't have knowledge of. I called the customer line and it sounded like it's all my fault. There is no security or assurance for my money. Mi believe that when I make a purchase there has to be a back n pin number. Now I have to pay for a new card and also for money for investigation that are going to take long. That was money meant for my daughter's day care fees😭. I just want money back n change this bank because now I fear for losing more of my hard earned cash.