Active Call not hanging up preventing future calls...
This is a known issue to Dialpad (they just told me after chatting with live support)
If you have this issue log on to the website and alert them via a live chat.
Phone support will likely not answer your call, killing the app. (in my experience) did not work, logging out and back in does not work, turning the phone off and back on does not work since everything is contained in the app. Don't delete the app. unless you want to lose all your data. Just initiate a live chat and they will kill the never ending "active call" from their end so you can place future calls. the previous call will call will still say "active call" but there will be no running clock on it so for the time being it appears to be a bug.