No paper trail ****

There's money that just goes off my bank account that leaves no paper trail and leaves the bank statement balancing back to your transactions. If i buy something lets from woolies on the 10th of the month, it will go off my account and i will get a notification of my transaction and balance afterwards. I then pull my bank statement a week later and i will find that my end of day balance is different. It shows that the transaction actually happened 3 days later and if i reconcile my end of day balances. The balances are different! I spoke to my banker about it and she referred me back to my statement. But really what the statement says and what really is going on doesnt tally back! something ********** is going on behind the scenes that cannot be traced! this has been happening now to me from August 2014 till now! but now i'm enough! my car installment bounced cause there were insufficient funds!! of which it shouldnt have happened cause i know how much i spent and what my balance should be and its never the same as what my bank balance tells me! this is it! i'm changing banks! I cannot have this going on anymore and the worse thing is that I cant prove this!!