If your supply is off but there’s credit on your meter, it could be a wiring fault. Check your trip switches.
If you’re not sure how to do this, or if the fault re-occurs, or the trip switch fails to re-set, it's best to contact a qualified electrician.
If there’s no display when you press the blue button, there could be a power cut. Call 105 to contact your local electricity distribution company, who'll be able to give you more information.