O2

Hi everyone. I change my tariff 2 month ago. From 17 May my tariff £25.61 but I paid £75 and last month I paid £80. I don't know why. So how can I cancel my account. Thanks the answer.

Hi. Can anyone tell me what is this? And how can I cancel this Premium text because every month I pay £80 and I don't know why and how.   

Hi everyone. I would like to ask how can I cancel this Premium text because every month I pay £75 or £85. But I don't know why. I tried to send Stop messages but nothing.