Messages getting stuck at the end of sending

I have an iPhone 5 running iOS 6.0.1 and often my text messages will get stuck at the end of the sending progress bar. Like this: http://i.imgur.com/iqxjo.jpg It'll slowly progress towards that point and then it'll just stop. It will sit there anytime from a few seconds to a few minutes. It usually happens to regular texts, but it occurs with iMessages occasionally too. I can assure you it's my coverage/Internet connection is fine when this occurs. I've contacted Verizon Wireless and they've done countless troubleshooting such as resetting things on their end, sending me a new iPhone, SIM card, etc. I've done restores, I've used it without restoring form a backup, on a new phone, etc. and it continues. This problem has NEVER occurred before I got my iPhone 5 running iOS 6. iOS 6.0.1 didn't fix anything. Considering iMessage is doing it too, I'm beginning to believe it's a glitch in iOS or the new iPhone. Please help, this is a really annoying bug and anything would help. Is anybody else having this issue? Thanks!