If you don't have a "Plans and Payment" under your account settings this means either:
a) Your subscription is via apple/itunes so for cancellation or subscription management please see the following: https://support.apple.com/en-us/HT202039
b) Your subscription is via Google Play, so for cancellation or subscription management, please see the following: https://support.google.com/googleplay/answer/7018481?hl=en&co=GENIE.Platform%3DAndroid
c) You are not signed in under an account with an active subscription. In which case we can help locate your active account by sending us any other emails you are associated with or the last 4 digits of the card being charged along with the date of the last pliability charge.