VM won't call you out of the blue to tell you of a technical problem. So if you get a call saying it is VM and they have detected 'problems with your router', 'hackers on your network' etc. etc. or any other such claims, that is always a scam call.
The fact you have posted two different numbers (and they have now been removed) suggests you have received two scam calls.
VM may well call customers for marketing purposes. You can opt out of marketing calls by logging into 'My Virgin Media' and deselecting marketing options.
Caller ID numbers can be faked by scammers to look like VM numbers so you can tell nothing about who is calling from a caller ID number alone.
Part of a scammer's routine is to create a sense of urgency in your mind and an idea that you need to act quickly so you respond to the scammer's demands without necessarily thinking things through during the call.
If you have any doubts at all about the authenticity of an incoming caller claiming to be VM, hang up. Wait a while to fully consider what the caller has told you and then place an outbound call to VM yourself using one of the recognised VM support numbers if you need to speak to VM.
