Just got the iPhone 6, - updated to IOS 8.1.1 calls failing

Hi

I just got an iPhone 6, updated it to IOS 8.1.1. I am getting lots of dropped calls, and calls that are not going through and resulting as "Call Failed." As well as distorted audio on calls. I've never had a problem before.. AT&T is saying it's the phone itself but I'm not the only one that this is happening to.

Any thoughts?

Thanks