FNB PATHETIC AT BANKING

I have an FNB cheque acc and recently took on a Life cover through FNB. My 1st installment was 26th April and yet I was debited on the 27th which resulted in no funds being in my account and I was charged R110 for an unpaid debit order, then I was redebited on the 28th of APRIL which was successful, again now 27th May same thing another R110 unpaid fee - its only this freking pathetic company which has resulted in unpaid debit orders as the date they are debiting is wrong and not as agreed the 26th of every month- I complained last week and was refunded my 110 for both months but still no explanation why I was charged 110 as it doesnt corresspond with the agreed rates and this was the 1st 2 unsuccessful debit orders . Today I was yet again debited and charged 110 for the unsuccessful debit order - why is 1 bank so *********** . I sent a complaint via email and still no response to this hour. I want this resolved asap and I do not wish to continue my life cover with you guys - FOCUS on banking as clearly this is not your field of expertise and I dont want to have any debit oredrs with you guys cos you also cant understand and keep to agreements