green call button wont make calls on keyboard screen

iPhone 5, 16gb, iOS 8.0.2

So I've been having this issue for quite some time....

Example 1: On the keyboard screen after I type out a phone number, I try to press the green call button and nothing happens. The phone is registering that the button is being pressed, but nothing happens. It just stays on the keyboard screen.

Example 2: I try calling a recent contact and press that number. Again, it knows that I'm pressing it because it highlights, but then nothing happens. It stays on the recent call list.

Since this started happening, I've run into some trouble with having to make emergency calls but couldnt because of this weird issue. In order to temporarily resolve it, I have to start my phone 2-3 times. It also randomly drops calls when I am in a perfect service area.

I appreciate any sort of insight and support for this issue.

Best regards,

Meghan