Loan application

I made a loan application with the bank during the month of January to the amount of R80000. On the 12/01/2015 I walked into the Marble hall branch to increase the loan amount to R120000( which means I added R40000 on top) .After the second application there were certain transactions going on from the account, including extra money that I did not apply for. I did not get any call from the bank regarding the money. I got a notification message on my cell phone about money being transferred out of my account from the marble hall branch. My credit moved up and the only call I got from the bank was to inform me that I have exceeded my limit and my instalment will increase. The bank took money from my account with my authorization, including the overdraft. I now have to pay money that I did not apply for, I did not sign any forms fro extra money