I assume you think its swim bladder becuase it is unable to control its position in the water, right? Thererfore likely either to be internal bacteria, injury, or a genetic weakness.
Am also assuming that you've ruled out other potential cause s of wierd swimming position, such as poisoning? So your ammonia /nitrites are zero and there is definitely no way fumes could have got into the tank, you've not changed the decor in the tank, either?
Bacteria infection - any deterioration in water quality or increase in stress for the fish at any point in last couple of weeks?
Injury - any damage in catching it, what are the other fish in the tank, how big is the tank, how big your angel fish?
PLEASE HELP!, I HAVE AN ANGEL FISH WITH WHAT WE THING IS SOME SWIM BLADDER PROBLEM! WEVE PUT IN SOME OF THE MEDICINE FOR SWIM BLADDER PROBLEMS AND PLACED IT IN A BREEDING NET SO NONE OF THE FISH COULD ATTACK OR EAT IT! HOWEVER THE MEDICINE DOESNT SEEM TO BE WORKING AND THE ANGEL FISH ISNT EVEN TRYING TO SWIM, THIS FISH IS ONE OF MY FAVOURITES SOMEONE PLEEEEEEASE HELP!!!!!! 
