I want to cancel a subscription but no option cancel ? How to canc it?

There is no option to cancel it though

You have to go to iTunes & App Store in your iPhone settings. Then click on your Apple ID, and go to subscriptions and you will see the app subscription there. You will be given the option to cancel it.

What does the renew say e.g. is it not currently set to renew and you are being given the option to restart the subscription ? If a subscription is active and will renew it should say when it will renew and give you the option of cancelling it (as shown on the page that you posted from), if it's already stopped/not set to currently renew you should see options to restart it

That shows that it's set to expire and end on 25th August, and that it won't renew unless you resubscribe via one of those three options

What options are you seeing ? If only options to restart or resubscribe it implies that it's already set to not renew

Does the subscription show on the account in the Subscriptions section at all ? If not you are sure that's being paid via that iTunes account, its subscription payments show on its purchase history ? If they do show try contacting iTunes Support and see if they can find and stop it renewing : iTunes Store - Contact Us - Apple Support