Your fridge won't go below 50*F? Are you sure? Tested with a few different thermometers? A good fridge can easily get down to 34*F.
Ok so gelatin would be your best bet for cold crashing... I've seen some people use Chitosan, however that is made from shellfish, so if you or anyone drinking it has an allergy you should steer clear. Quik Clear is another, you could use...
Personally I love gelatin. Try that... Take about 1 cup of near boiled water and add 1 tsp of gelatin to it (get this at your Local HB store) and stir till its completely dissolved. Cool to around your beer temperature and add to fermenter, gently mixing it in with a sanitized spoon.
Try and cold crash it for a few days... Even let it go another week. Transfer to your bottling bucket (I'm assuming you are bottling) Add your priming sugar or use carb caps and bottle it.