Acc balance never correct

I moved from a savings account to the Savvy account and find that the account balance is always incorrect or misleading. When you logon to internet / cell phone banking the balance will be x but a day later it is different. The issue is that they show current and available balance which is never correct. As a customer if you have funds in the available balance, that is what you can use. Also the sms balance we receive does not tie back to the statement. I did not have this issue with the savings account - Every swipe reduced the balance correctly so why does the current account not work the same?