UNEXPECTED DEDUCTION!

I am so angry with FNB!!! Wpke up today to a transaction that I had done on the 26th being deducted on my account! Kanti what's the point of reserving the money when purchases are done??? Now I have a huge negative balance on my account and this is not the first time this is happening... I am so angry!!!! I will be closing all of my accounts with them after this! I am migrating to more user friendly banks!!! We can't live like this