I have paid through Google Playstore, cannot see an option to cancel auto-renewal on the app?

For Google, auto-renewal can only be canceled from your Google account, whichever you have used while subscribing. Click on the respective mode of your initial subscription below and follow the instructions to cancel the auto-renewal.

Here are the steps:
-Launch the Google Play Store app.
-Tap Menu -> My apps -> Subscriptions and tap on the app of the subscription you'd like to cancel.
-Alternatively, tap Menu -> My apps -> Tap the app of the subscription you'd like to cancel -> Tap the app's details page.