FNB worst benefits and the most unauthorised charges

Please advise me as to why FNB charges you a monthly fee which is meant to cover certain transactions yet I am continuously being changed random fees. First i was getting charged "Its on me" for which i was reimbursed a minuscule amount in comparison to what i was charged. Now I'm being charged a "payment bundle fee". I have absolutely no clue what this is for, the days i was charged i hadnt even made any payments. I have been charged R150.00 in less than a week. I need an explanation and refund!