I pay $.99 per month for additional storage and I keep getting an email that I’m running out.

If you are at or near your 50GB subscription limit, you will be constantly altered to the fact your storage is almost full. When your storage is full, you risk losing icloud emails, failed backups, corrupted data, so the nags will not go away until you free up space or subscribe for more storage.

It really is no different than your Mac or Windows computer nagging you when your hard drive is nearly full.

As I already told you, unless you delete material to free up space, the nags will never stop. You have 50GB available to you. If that is full, the nags will continue ceaselessly, until you delete material, or subscribe for more storage.

You don’t get an incremental 50GB every month. You get 50GB total, and you pay monthly to keep that (consider it a rental fee for that wedge of storage space on Apple’s servers).

I'm paying $.99 per month on credit card and need to know what I'm paying for??