Since the switch from EE to O2 my phone has become very unreliable which is not great as I use it solely for work.
I live in an area with poor signal, however a couple of years ago an EE mast was installed which is why I got a contract with Virgin. Generally in the house I used WiFi calling as the signal wasn't reliable enough to solely depend on it.
Since I got my new SIM card earlier this month and the switch has been made to the O2 I can hardly make a phone call, occasionally it works but usually once I've dialled the number it just offers two options, a call failed button and a redial button. Sometimes if I turn it off it works but not for very long. When people ring in it usually goes straight to answer phone so I pick up the messages when I go out and get signal.
Alternatively I get a message to say I've got a voicemail even though the phone hasn't rung, but I get the same option when trying to call voicemail of call failed or redial. Again sometimes if I turn it off and on again I can listen to the voicemail. If I'm lucky I pick up all of it and if not the call fails part way through listening to the message.
Also the numbers usually show in a funny format, rather than the regular 07123 456789.
I'm on software version 15.4 and my phone is an iPhone XR. If anyone has any suggestions as to how to sort this out I would be very grateful.