Account balance keeps on increasing

Opened an account with them. Never skipped a payment but for some reason the balance keeps on going up. Went to the store to ask if I was still subscribed to one of their ridiculous magazines or whatever ( I was previously subscribed to one unknowingly ?) but the lady told me no, just got charged an extra R11 intrest. What’s upsetting is that I’m paying R34 extra for what?! I don’t even know!! Nobody is helping at all. Can’t wait to settle the account and be rid of this loan-shark company