Also if anyone does get these calls trying to ask people to dial premium numbers - you should report them to
ICTSTIS - they will need the premium number that you are being asked to call.
I had an interesting one over the weekend on my mobile - a text message from an 0871 number, claming to be my voicemail and asking me to call the number to retrieve - 0871 numbers are nation rates.
Apparently if I had dialled it, I would have prompted to call a premium rate number. But by the time I did icstis had taken them down!