You are right. I guess you were bitten by the restore from backup.
The backup must have the messages locked up. Without doing a full restore you could go to Settings -> General -> Reset -> Erase all Content and settings.
Nope, not been paying attention at all.
Deleting them through the message app does not free up the space
You delete them from within iMessage. It does delete them and reduces the storage
OOOhhhhh.... I see what you did there. "These aren't the droids you're looking for" very tricky!
Lol, not sure what you're talking about honestly. All I was saying was I had no issue with space/messages. All seems to be working correctly. As it is for others as well.
Clearly it's not working for the OP and at least some others who have posted similar things in this thread as well. So, it's definitely great that it's working for you, and perhaps even many others, but the point is that there's an issue with the functionality, otherwise it would work just fine for everyone (OP and some others with the issue included).Lol, not sure what you're talking about honestly. All I was saying was I had no issue with space/messages. All seems to be working correctly. As it is for others as well.
It's the attachments that are taking up your storage.
There was a bug prior to 6.0 or 6.1 (dont remember which version exactly), where attachments were not deleted even though you deleted the message/sms threads.
While the bug was fixed, only attachments in current message threads will be deleted. Any orphaned attachments are just stuck there in limbo hogging space. Orphaned meaning attachments in which the original threads have long been deleted, prior to the bug getting fixed. If you've never deleted anything, this probably won't affect you.
I only know of two ways to fix it.
1. Restore the phone as a new phone, not from a backup, and essentially start all over from scratch. All those orphaned attachments are stored in backup files.
2. Jailbreak, locate the attachments folder for SMS/Messages and delete everything in there. (This is what I had done while still on iOS6. I saved over 1GB in space).
I have reported it to Apple, and I feel that anyone who suffers from this should report it too. The more of us that report the same issue, the greater chance we have of Apple actually fixing it.
Mine takes up 10.2GB