******* practices at FNB

I have a revolving credit account with FNB (as well as 'n current account and everything else). At the end of the month, their were R19000 available in that account. So at the end of the month, I paid in another R4000. Bringing that amount available up to R23000. On the 10th, FNB deducted R1200 (debit order) from my FNB current account to my revolving loan. They also deducted about R300 interest on the account. But, even though they deducted the debit order, its still not showing in the revolving credit, oh its sitting there but its not added to the total. So the 23000, is now sitting on 22600+. This all happened on the 10th. So basically, for 4 days now, they are adding extra interest on the revolving credit, because the R1200 is not reflecting in the total, and paying me less interest on my current account because the R1200 has already been deducted. When I phone them, I get told its not been cleared??!! 4 Days and its still not clear, and its not even from a different bank! Thats how they are fleecing their customers. I am cancelling the debit order, and will roll it back everytime it goes off, I am not paying a cent into that **** anymore