R620 a Month standard bank chargess after an "upgrade"

i never really check my bank statement. Today I did and see that my monthly Service Fee is now R620. I am not told that is standard charge for my "upgrade" I agreed to. This is madness and I would never ever have excepted this "upgrade" had this been explained to me. I tried communicating with FNB but this is always challenging as speaking to a human is close to impossible. Imagine that charge on a very average salary!