take it out of the fridge put it in a 70 degree area. Maybe give it a swirl or two wake the yeasties up a bit and wait three weeks. I accidentally put a 6 pack in the fridge from the wrong batch a few months ago. pulled the other 5 and let them sit till the end of the batch the belonged with was gone and refrigerated them last they carbed up fine.
Once you warm them up, you only need to roll them on the carpet or gently tilt them back and forth once. That's plenty to re-suspend the little bit of yeast needed to carbonate.
Then, leave them be for three weeks at 70-75*F. After that, fridge a few for 3+ days before popping a top.