No point trying to repair it. 10 years exposed to the elements? If the solar panels aren't choked with dust or the electronics aren't damaged from the Martian cold/hot, the batteries have most likely lost their ability to hold a charge.
The only reason the active units survive so long on the red planet is they can deal with the various dust storms, flash freezes and the like that Mars throws at them by keeping themselves internally stable, if Beagle 2 hadn't deployed properly there is no chance that it'd be able to keep itself alive for 12 years, and even if it did, that's beyond the life expectancy of a standard mars mission anyway.
It's functionally, financially and professionally more appropriate to launch a Beagle 3, and maybe one day if a manned mission reaches mars, they can investigate the probe with a person out there, or just declare it as a memorial/marker.