We switched to Virgin phone and broadband a couple of months ago, part of that was also the phone being VOIP (voice over Internet protocol) since that time our telepohone answering maching records roughly every 30 minutes 'NO NUMBER' the phone doesn't ring but the caller list fills up and we are missing important numbers when we want ot get back to someone. We have to empty the caller list each day. We didn't get this with BT. Is the VOIP doing some sort of check every 30 minutes on the line and can we stop it showing these calls on the CLI.
Sorry to hear about the problems you've had since switching to VOIP. Being honest I'm unsure what would cause this, but I'd like to take a look and see if we can identify any obvious issues - failing that we can arrange for a tech to investigate further.
Please look out for my PM so we can confirm a few details & we'll take it from there.