FNB Lack of Service or Staff ?

Good day, I would like to complain about the lack of service at the FNB Highveld Mall branch in Emalahleni. I was at the bank on the 3rd of July 2019 from 3pm and only left at 4:30pm, then again on the 4th July 2019 from 9:30am and until 10:35am as this how long it took me at the tellers. My main issue is that it is peak time end of the month therefore the bank is understandably busy around this time of the month however WHY is there only 1 teller open / operating at the tellers. Why does the bank even have 4 teller counters when only 1 is operating. What is the point ? I was told by an FNB employee the system is slow therefore there is a delay as obviously people in the queue just like myself were visibly upset and disgruntled but then why do you have only have 1 teller operating, if its lunch time it is understandable but this is early morning and the bank has just been open for an hour or more. Is the bank under staffed ? What is going on ?