Once you delete a text message, it won't appear on your device but stored in the cloud. Now, if you want to erase the message permanently, you have to follow certain steps:  Step 1: First, you have to go to Settings on your device and click on the General option. Step 2: Then, click on "Storage and iCloud Usage" and followed by "Manage Storage" under the section of iCloud. Step 3: Next, choose the device you wish to delete under the option "Backups." Step 4: Now, scroll down to the bottom and press Delete Backup Step 5: Lastly, click on Turn Off and Delete to erase all the backups.