Hi there @Flávia25,
Welcome to the Community!
Hope you don't mind us replying in English, since that's the official language of the forum.
Have a look at this Support article. What has most likely happened is that you've joined the Family plan with a different account than your original one. So you most likely have two Premium accounts active. You can also have a read here for more info on how you can find your second account and cancel the Premium subscription there.
Hope this helps 🙂
Don't hessite to reach out again if you have questions.