They are in my dark basement...sitting at about 60 degrees. They arent sweet.....just flat. And unfortunately I dont have really good notes (have learned I need to).....but my recollection is that I used 5 oz for the 5 gal batch. Thinking back that sounds low maybe not ? I bottled about 5-6 weeks ago.
5 oz sugar should be plenty. 60 degrees is a little cold but if you don't taste sweetness from the priming sugar I don't think that is the problem. Do you hear any hiss at all when you open a bottle? Have you tried a bottle from several points in the filling process? (i.e. a bottle from the begining of the bottling session and one from the middle and one from the end)
What kind of bottles did you use? are any of them twist off? these have a tendency to seal poorly.
If you can determine what exactly went wrong you should be able to fix it. But it is going to be a hassle no matter what.
If the yeast was pooped out you can open each bottle and give it a little squirt of rehydrated yeast (just a couple ml)
If the sugar was insufficient or missing you can open each bottle and drop in a carb tab or a measured amount of sugar syrup, and maybe a squirt of yeast
If the problem is bad caps or bad seals you can do option 2 above as well.