How can unauthorised orized debit ammounts be debited

How can you let unauthorised ammounts be debited from my account there is 2 payments which is not the ammounts that was authorized as i paid it manually the bigger ammount. I did not sign for those ammounts to be debited and i can not reverse them online. I will not pay for thid transactions to be reversed nor the bank costs i feel like i want to change my bank accounts all of them over to another banker today