If you are a part of a family plan subscription and you want to cancel it without contacting the main family plan subscriber, please follow the below steps:
1- Go to your library
2- tap on settings
3- Go to subscription
4- Go to manage subscription
5- tap on "cancel subscription"
Or in case you are using the web version, you can go to https://www.anghami.com/manage-account and tap on "cancel subscription