R700 bank charge

i am so angry i5s not even funny. I want to move back to Absa now. On the 26th i had debit orders n they all debited fine, then the next thing,i was charged x5 R138 in my account for insufficiant funds. a lovely consultant at FNB Rosebank tried assisting me, logged a query for my refund they rep**** the want proof like really proof coz they have my bankstatement with them. really now. Its out of order i work hard for this money n then FNB takes it like its theirs. I want it back..... before i get my lawyer involved.