It's part of their script, they get lucky on some, some they don't.
The only thing I can advise is to maybe purchase a call screening handset which I cannot guarantee would stop the calls, I can only go off personal experience that since installing one, we don't get any spam or sales calls.
Same here: Had a call this morning and they told me they were from virgin media and were calling about router speed. In order to investigate they wanted me to log into my pc and they would talk me through what was needed. I asked them how they could investigate the router and what information was required as I could browse to it and get error logs. They then said it was very technical and better for them to do this, which means they would require remote control of my pc. I told them I was a retired Cisco Certified network engineer (which I am) and then they hung up.Phone number they called from was 01252 Area Code which I think is Aldershot.
I have just received one of these calls. Very amateurish but some people would be fooled into downloading some malware. They need to work on their script to be more convincing. I played along until they wanted me to get onto a laptop. Stephen Warner
Had two calls yesterday - one from 01783 939492 and the other from 0151 201 8238 - both claiming to be from Virgin Media and saying that lots of suspicious messages were being downloaded every time I connected to my router. Put the phone down. Please can you confirm that this was not Virgin Media?
It would be helpful if you were to post a message quoting the numbers that Virgin Media would call from or the reasons they would/would not call - something to help people determine if the calls are genuine or not e.g. say that you would always send an e-mail or text before calling?
The two numbers are fake and the calls were attempted scams. Scam VM calls frequently mention "your router may be disconnected in 'X' hours" or the scam caller wants to "change the settings on your router".
You should not rely on a caller ID number as proof that a call is coming from a specific person/company. The caller IDs can be easily faked and this is part of the scam in generating a false level of trust that the call might actually be genuine. VM does have known numbers which they may call from for the purposes of marketing but seeing those numbers on caller ID does not mean the call is 'safe' (which is why publishing a list of them would be counterproductive).
You can opt out of genuine VM marketing calls through 'My Virgin Media' and communication preferences. You can also register with the TPS which will stop legitimate companies contacting you.
You need to apply some general principles to spotting a scam call or text or email. Some links with general advice are below.
Alternatively, screen your calls via answering machine or look at getting a call blocker/screening device/phone.