British Gas prepayment meter

Our pre payment meter is blank - we had a powercut in our area , the gas the electric all went out. It came back on and now the screen for the meter is blank - no numbers nothing. Strangely the gas pre payment meter switched back on fine. So i’ve tried holding the blue button for 30secs nothing, tried switching electric off for 40 mins then switching back on - nothing. I have no way of seeing the balance . Can i fix it or do i need to get a British Gas Engineer in? I really don’t want a smart meter .