Every time I delete my iPhone messages they reappear?

I have iOS7 on the iPhone 5. My phone's capacity was full so I deleted some music and photos. I'm attempting to delete the messages. I swipe to delete like normal, they disappear and then when I go to click on a new message I just received, my phone freezes. Then I quit the app through multitasking and then reopen the app and all the messages are gone! Completely. Even ones I haven't deleted. Then I turn my phone off, turn it back on and all my messages are there. Even ones I have previously deleted. I just want space on my phone. How do I delete my messages?

Sign out of iMessage reboot the phone then sign back in.

It it the iOS but that lead the cache to be recovered. New iOS 7.1 beta is coming. You can wait the official iOS 7.1 and update your iPhone. It has fixed a lot of bugs and you can have a better experience.