FNB excess fees and poor secure chat facility

Excessive penalty fees charged against my account due to the banking process between merchants and bank being delayed. SO I get penalized for transactions I execute when there are funds in my account, and due to a faulty or delayed process, the transactions are processed when the funds are not available. FNB then process the transaction, but penalize me heavily with an excess fee penalty. These transactions go into a "Pending" state in my account, Surely they should be deducted from the available balance and held in reserve for the transaction to be processed? Highly unfavorable as this affects my cash flow and my credit rating. Tried to get assistance from FNB, secure call does not get answered and secure chat is administered by people who decide to end the conversation when they don't feel like assisting anymore. Took me over an hour to go around in 5 circles and still not be directed to someone who could assist. Just cut me off!