Calls diverted to an unknown number

[Citron2010]

Hi,

I'm having to resort to posting on this forum as chat doesn't work and support lines aren't open.

I'm reporting this on behalf of my father who's 90 and not great with tech.

Whilst trying to change the amount of time before calls are diverted to voicemail, I noticed that his calls were being diverted to an unknown number if he's not reachable or if he's on another call.  I tried calling that number, but it just goes straight to voice mail.  I don't want to publish that number here, but could there be any explanation for this?  I doubt he's set that up himself either deliberately or by accident.  I've now reset both scenarios to divert to voicemail.  

Thanks

[pgn]

If a smartphone, @Citron2010 - could be from a link or website. If a plain old dumb phone, butt-dialling or typo. Would be my guess...

And X or FB links below will help you chat to UK-based O2 support personnel.

[MI5]

or his O2 voicemail number.

07860 980980

Guide: All you need to know about O2 Voicemail 901 

[Oxonian]

This might also be of use to you @Citron2010 :-

Guide: All you need to know about O2 Voicemail 901 

[Citron2010]

Sorry, I don't understand?

[Citron2010]

It's an iPhone.  I can't believe he's managed to set both diversions to the same number by butt dialling.  I'm just trying to figure out the exact vector that it could be done with a malicious link?  Maybe something that dialled the commands to set these up?  Possibly some link that did the same via either the web or mobile app?  But that would need to be authenticated.  As far as we know, he's not been hacked (email/banking etc.) - but I'm going to change his O2 password just in case.

[MI5]

@Citron2010 

901 is not the only number that gets you to your voicemail.

The number I posted also does, but as we don't know what the number you have is.........?

[Citron2010]

Ah - OK - no, it's a different number.

[MI5]

Have you Googled the number for any clues @Citron2010 ?

[Citron2010]

Yes - no results.  I've even left a message asking to call my number back!