My Contract termination date incorrect

My contract was supposed to end on 25.10.2015 but since i couldn't give them a notice before 3 months i called customer care to terminate she said we can't because i didn't give a notice before 3 months. But then i asked her to cancel the contract she said she can extend it for 6 months and i would be charged 8,99 Euros instead of 9,99 Euros. But now since its April 2016 i checked my online O2 account it says my contract is till 24.07.2017. I want to cancel this contract. I think there is a big miscommunication. Please cancel my contract.