money lost

On the 30th of July 2019 my credit balance was R1297.30 at 16H16 i made a purchase at Capella and R400 was debited from my account and i also got a sms notification with the remsining balance of R897.30 in my account. I made a special arrangement with hollard to deduct R222 and R120 on the 2nd of August 2019 for my policies that i have with them. I believe they deducted them today although i didn't get the sms notification for those debit orders. When i checked my balance this morning my account was on a minus R399 of which i don't know anything about it. I called the FNB Customer care line of *** the lady who helped me was so rude to me and when i tried to explain my side of the story she said because i know too much she is transferring me to another consultant and my airtime was running out. Eventually when i got hold of another consultant, he read out my transaction history for me, but the balances that he read out were different from the balances i had on my sms notifications. When i asked him where can i send him the proof of the balances that i received via incontact services he referred me to another department. This is the first time something like this happen, a debit balance that i know nothing about or loosing losing money in my account.