Separate debit orders charged as unpaid while theres money in my acc

Fnb secure chat on my app is not working, i also do not understand how separate debit orders where reversed while theres money in my acc only to be charged as unpaid fee. What is going on with fnb? I'm appalled by the service cause I don't understand how 2 separate p/loan debit orders are both reversed only to be charged as unpaid. Please explain myb I'm missing something.