been having these random numbers and mobile numbers calling me. first few times i answered because i thought it was my boss or a phone call i was expecting... it would hand up immediately and when i tried to call back it would go straight to someone's answering machine or voicemail. these scammers are getting a little experimental and i wouldnt chance any phone call. my word - if its important enough or a real genuine person they will leave a voicemail otherwise i dont worry about the number, i just report and block it. never answer these calls, they record you saying 'yes' 'no' 'hi its ****' pathetic scammers.