FNB *****ed up debt orders

So its a little long winded but I am seriously disappointed with FNB, on the 1st of August my debit orders ran, on the 3rd I receive sms, email, the stupid app messages stating the transaction failed due to insufficient funds. I had, have money in my account and yet the debt order returned the money it took, FNB then charges me for the supposed insufficient funds, now I get to explain to those that didnt receive their payments and look like a complete asshole, I tried calling, there is either no answer or the bot hangs up on me, I tried twitter no feedback, I tried the stupid secure chat app and nothing, basically speaking to myself, I want a full explanation on why this happened and it better not affect my credit rating as a missed payment! even the SMS's i received from the debt orders stating the money I had remaining and there is no negative amount in my account!