Tap scanner(scanner app to pdf)

I downloaded a free scanner called tap scanner(scanner app to pdf). On may 18 2020, they deducted R899.90 from my account without my consent. I dont know how they got my banking details. When i did a research to find out whi deducted my money since my bank wouldn't help me, i discovered it was tap scanner (scanner app to pdf) premium 3 day free trial which i never joined. They are fradulent.