Recieved a sms today. Exactly like this;

Sender: CALLMEBACK
message: You've been sent this message by +anonymous who has asked for a call back on 03/02 at 14:41.

i tried calling back by pressing the call button to see the number and it does not connect, however i see the number and it is 225-563-2225.

Im in the UK so i dont have a clue of any service like this available here. any help?