My icloud was updated monthly until now. I dont know what is happening i cant change my plan back up can you help me?

Hi Emiktu1,

Thanks for using Apple Support Communities. When your payment method is declined you can use the steps below to add a new payment method:

1. On your iPhone or iPad, open the Settings app.

2. Tap your name.

3. Tap Payment & Shipping.

4. Add a different payment method and remove the old one. 

5. Try to complete your purchase.

See more about those steps here: If your payment method is declined in the App Store or iTunes Store - Apple Support

Thanks.