Cannot disconnect from voice mail

[jessesmith]

Problem description:
When I call my phone carrier's voice mail (by dialing my own phone number), the Ubuntu phone app immediately reports the call failed and returns me to the dial screen But the phone app leaves the audio connection active. This means I can hear the answering service's menu prompts, but cannot respond to them as I have been returned to the phone's initial screen. Pressing numbers on my keypad simply put them into the "number to be dialed" box.

There is no way to terminate the voice connection in progress. Trying to make a new call fails and closing the phone application does not terminate the call.

The only way the call ends is if the remote computer hangs up (after a few minutes of no response) or if I reboot the phone.

Expected behaviour:
there should be a hang-up/kill button on the dial screen to terminate any lingering calls in progress. Alternatively, quitting the phone app should cause the connection to be dropped.

OS: Ubuntu Touch 15.04 (r14)
Model: Meiuz Pro 5