Calls all dead. Is this bye bye phone?

[sam59]

Since the Kitkat update, my volume slider hasn't worked. I've had to adjust the volume by going into settings.
The slider bar just won't move.

Worse happened today - I managed a few outgoing calls this morning, but that's now dead, as are incoming. No sound at all on the line.
I can only use the phone for texts.
Is this bye bye phone or is there anything I can do? I own the handset outright so no mobile operator to help out. I'm in the UK. Thanks.

Edit: phone has just updated Kitkat to 4.4.2 and touch wood, it's all working again. Is KK buggy? (yes)

 

[Haalcyon]

Wow. Yeah, I think KK can be buggy on one device and work beautifully on another. I'm glad it straightened itself out with an update.