Overcharged on bank fees

I have a savvy bundle account, which is R190 a month, where all the fees are included.

I was charged an additional fee of R40. I would like a refund for this as it is incl. in the R190

I called the contact centre . They said i should go to the branch.

Why should I go to the branch for a billing error you guys made.

Please refund me my money!!!!!!!!!!