on 28-11-2020 21:32
You need to report it via this route Guide: Lost or Stolen O2 Device? - How to Report it
O2 will then send you a replacement.
No. you aren't able to find out your number using any sim.
O2 will have a record of your number and will give it if you pass security checks.
on 28-11-2020 23:27
Do you even have any signal on your phone? Try calling voicemail on 901. If it doesn't work, then it might be the sim needs to be activated. I've never heard of the 2020 service only working on a certain type of sim.
I can see you are enquiring about a Pay & Go sim, have you topped up for the first time yet?? This might have something to do with it as well.
On the subject of voicemail, here are the settings:
Turn on diverts to Voicemail 901: dial 1750
Turn off diverts to voicemail 901: dial 1760
If you don't want voicemail, you can use O2 call alert by dialling 1710. You can turn this off by dialling 1760. O2 call alert is like voicemail but doesn't let people leave a message it just let's you know who called and when providing they didn't withhold their number. Voicemail 901 also let's you know who called if someone hangs up before leaving you a message.