same as many others, no ringtone on landline handset

Called 150 yesterday. It was claimed that it was a handset fault, not a line fault. The first person prevailed on me to have a special device (whatever that is) inserted in my landline box (whatever that is) for the cost of £10. I was then moved on to a second department, Device Rescue, who then moved me on to a third department, Virgin Media Faults. The lady there suggested I unplug my router and then plug it back in again. My wife did this but of course that cut off the call.

This sesms to be happening to a lot of people. Why?