Need my money back

The worst service ever , FNB has been deducting money on my account saying its for items paid with no funds- been calling because I have not been on a minus - no one can give me answers- Spoke to Thami and he kept me on hold for over 30min , clear he wanted me to hung up I mean you cant say to me please hold I need to check something and keep me on hold without any update , I'm enough with this bank, you **** me then cant give me answers