OKLAHOMA CITY - A new iPhone setting has many users doing a double take when they get their bill.

A new setting on your iPhone could cost you thousands if you don't manually turn it off. It's called WiFi Assist, and it automatically switches your phone from WiFi to data usage to make sure you get the best signal when surfing the web, and when a strong WiFi signal isn't detected.

The new feature comes with the latest Apple update. While some may like the feature, one Apple insider says many don't know it's there.

To turn off WiFi Assist on your iPhone: Go to "Settings," then "Cellular," and scroll down all the way to the bottom to switch WiFi Assist off.

This isn't the first time Apple has been in hot water over this feature. Back in October, Apple was hit with a $5 million class-action lawsuit by a couple who say they were unaware of the feature and rang up large phone bills.

So far, Apple has no comment.