I answered a call from 0709 980 71304 yesterday from somebody saying "Hello, can you hear me? Hello! Hello!" and then he hung up. I was about to call this number back, but as I did not recognise the voice or the number, I decided to first Google this unfamiliar 0709 prefix. Luckily I did, as I found out that it was a phone scam to a premium number which can cost up to £50, had I called it back. So be warned!!