Help?

My phone acts like it has a low signal (though it does not, I clearly have full bars), and takes forever to send a message, then, according to others, sends the message around 4 times in a row! It just started doing this out of nowhere today. Sometimes it even says it was unable to send when it actually sent it the 4 or more times...I've tried restarting my phone and everything I can think of but the problem persists. I have  Coolpad quattro 4G. Any help would be greatly appreciated.