renault scenic expressions?

My renault scenic expresions (04) has locked me out! Neither of my cards will work - there seems to be no power at all. I was due to take the car into the garage tomorrow as the timing is off and the car is losing power - this is only since I had an MOT and service! I changed the battery a couple of months ago, and has been driving like a dream until this week. I can't open the cover on the handle to use the good old fashioned key - any ideas?