If you've answered a phone call from an 070 (or 076) number and instead of speaking to you, the caller immediately ended the call, (or maybe your phone has indicated there has been a missed call), then the advice from OFCOM is not to return the call.
"Consumers are warned about a scam which is designed to make them think they have received a missed call from a mobile phone. When victims call the number back, they are actually dialling a service costing up to £1.50 a minute.
The scam begins when you receive a missed call from a number beginning 070 or 076.
These numbers are used because they look like '07' mobile phone numbers but can cost considerably more to call.
When you ring the number back, the call is immediately dropped or an engaged tone is played and the victim is charged. Some callers have also heard a recorded voice suggesting a bad line, encouraging the caller to ring back and be charged a second time.
If you receive a missed call from a number beginning 070 or 076 that you do not recognise, do not call it back.
If you receive a missed call from a number beginning 070 or 076 that you do not recognise, do not call it back. Instead, make a note of the number and complain to the premium rate regulator, PhonepayPlus (Tel: 0300 30 300 20)."
Just passing on the information having received yet another of these calls this morning (but didn't ring back). Now reported and blocked the number.