I just purchased more storage and it’s still showing full. What do I need to do?

Can you explain further?

You just purchased more iCloud Storage?

What is full... your iCloud storage or your iPhone storage?

Note that buying more iCloud storage does not expand the capacity of your iPhone storage..

How to check the storage on your iPhone, iPad, and iPod touch - Apple Support

Manage your iCloud storage - Apple Support

You cannot purchase storage for your phone. What you purchased was iCloud storage, which can be used for syncing and backups. Your phone will never have more storage than it did when you bought it.

Go to Settings/General/iPhone Storage, see what is using space, and delete non-essential items. If it shows that “Other” is very large, continue reading.

Normally Other is everything that is not in one of the colored areas. If Other is very large there is something amiss in the storage area on your phone. 

The best thing to do is to contact Apple support using this link—>https://getsupport.apple.com/. Apparently they can fix Other problems remotely.

You can try fixing it yourself:

• Back up your phone to your computer, iCloud or both (for belt-and-suspenders added security)—>How to back up your iPhone, iPad, and iPod touch - Apple Support
• Restore the backup you have just made—>Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

Here is additional information on Other—>What is "Other" and What Can I Do… - Apple Community

However, Apple is investigating reports similar to yours, and any feedback you can give them at the above support link would help them and you.