Do I get a new 50gb of storage each month or what am I paying monthly for?

So I have? With this question. So since I bought the 50 gband backed up and by end of month I didn’t use the 50 of course but.... now my phone won’t back up. Says time remaining for back up is 7 hours... is that because I didn’t get on iCloud to pay the next months payment... and iPhone keeps booting me off my apps or won’t let me wake up an app from iCloud cause it’s saying device is full

If you pay for 50GB of iCloud storage, it's not cumulative, meaning you don't get 50GB each month. Think of it as renting an apartment to keep all your stuff, month-to-month.