My callers can't hear a dial tone

[VicSneds]

Ever since I have had my phone I have had problems with the voicemail... Originally the voicemail did not work so I had to have o2 set it up as it didnt recognise me.

Now I have voicemail turned on, apart from it doesn't work. Although my phone rings out as normal, the person calling me hears one dial tone and then silence for a while then 2 beeps and it cuts out. If they stay on the line my phone says I have had 2 missed calls (even though they have only dialed one).

I called o2, who changed the settings again. Following that it didn't ring at all and went straight to voicemail.

When I dial 07802 090100 as they've said I need to reset my voicemail pin to resolve the problem it just says that 'your number is not permitted to use this service'. I've been told that it has been reset, but yet I am still getting this message.

At present even though voicemail is switched on when someone rings my phone they hear one ring noise and then silence before 2 double beeps cuts them off. 

At my wits end... have missed a job offer due to this rubbish phone. Noone seems to be able to help and everytime I ring o2 they tell me its fixed, and it isnt.

Can anyone tell me a solution...?

[MI5]

@VicSneds 

All we know about voicemail here Guide: All you need to know about O2 Voicemail 901 

Try dialling ##002#. This is the short code to cancel all diverts, including Voicemail 901. You then need to dial 1750 to switch voice mail back on 

[VicSneds]

Hi MI5 tried all of this. Issue started when I added my apple watch, I see a handful of users have had previous issues... any idea on the fix?

[MI5]

@VicSneds 

That will be the well known eSim issue that seems to effect some accounts.

You'll need to escalate it to customer services Guide: Coronavirus Community Help and Support 

The best number to get through seems to be
0800 587 4005