unknown chargers

opened an account on November 2014 at waterfront branch and only started using it in October 2015 i deposited R40 on the account ,in November i was charged R160.00 they also they don't know what is it for .they just told me i need to go the branch were i opened the account which that is *********** of them because its the same company and i don't understand why should i do that and they sad they would do investigation but till now no feedback. so disgusted and very angry with this because this is my f*@k money at the end of the day . i even consider of close this account .