Unauthorized Debit orders R99.00

My account is repeatedly debited with R99.00 every now and then, like now i have a debit order that went through on the 15th of October and 2 more debits with R99.00 again on the 23rd of October with totals to R300 that i have lost in 8 days. I called FNB on several occasions asking them to reverse and block the debit orders and the last time i reversed this debit orders i was told that to reverse a debit order i will be charged /-R66.00 and today i called to get this blocked and reversed and I'm told that to reverse a debit order i will be charged R250.00 per reversal imagine. I have to pay R750.00 to get my R300.00 back. FNB is reaping us off cause this R99.00 **** is being going on for long and as a Bank there is nothing they can do to stop this from happening? Why is it not happening from other Banks? And with this fees that have been hiked with over 100% increase its making me wonder if it not FNB debiting customer's accounts and make it looks like its external debit orders.<br> This is not fair because FNB is not even helpful on this issue