Opening up unauthorized accounts and *****ing money

I have endless issues with FNB deducting money from my account without authorisation.

I had an amount of R300.00 that was taken off my account for some investment nonsence that I dont even have an account for.

When I spoke to the people on the secure chat I was put through to multiple different departments, then was advised the R300 was credited to a cash investor account. I do not have any investment account what so ever!!!! I want my money back that you have taken from me, this is the second month I have had to complain about you guys taking money off my account!