*********** workers and charged me unpaid item fee

on the 28 jan i checked the balance that was on my account, then on 30 jan i received my salary,,,,then i made 3 transactions which was withdrawal, transfer,and swiping only on this day, then the following day 31/01/2015 i withdraw some cash, then sunday 01/02/2015 i did nt use the card because of the debit that was going to run on monday,,,,on monday i didnt check, but Tuesday 03/02/2015,,,,i was sure that the debit went true then i can go and use my money,,when i went to buy some stuff the card was declinining, then i went to the atm,,the message was saying your transaction cannot be completed,,,,i was asking my self why? it was closed already,,,,now today when m checking the internet banking it says i have an unpaid item, they charged me for that,,why? whereas there was money in my account? another thing it was showing the very same amount that they reversed as unpaid item that they have paid on 02/02/15,,why do i have to go to the bank all the time when m getting paid,,,why does this bank employing uneducated people to mess up with my account all the time? why?