IPhone 5s :: FaceTime Not Connecting On One Of Our Phones

My wife and I both have a 5S running 7.0.2. A while back we started having issues with FaceTime connecting and I was reading that the Apple servers were having issues so I thought it was a temporary thing, but it has continued for months. I was able to use FaceTime on my phone to others, but she could not. Recently, we exchanged phones, and I reloaded ALL of my data and SIM card onto her phone, and vice-versa.  Now I am the one who cannot use FaceTime and she can. I have logged out of the Apple account and resigned in with my ID, rebooted, etc., but nothing allows me to make or receive FaceTime calls. If I try to answer a call, it just stays at "Connecting..." until it times out. If I try to make a call, it just rings and rings and then tells me the other person is not available.Â