Is he in QT? If you can, please qt him. Lets try one more thing before giving up!If you dont have a qt tank, a large plastic storage bin (20-30gal) with a filter & lots of air will work(air stones/bubblers). Keep the temp @74. It is absolutely vital that you keep his water perfect (0 amm, 0 nitrates, few nitrates). Dose his water with aquarium salt as you would do for ich. Go buy Maracyn & Maracyn 2 (made by Mardel) and follow the dosing instructions provided. Both products can be used safely together. One attacks gram+ bacteria & one attacks gram- bacteria. After the 1st course of treatment, you may have to follow with another. I suspect your dealing with columnaris rather than a fungus because the fungus meds arent working. That said, how are your tanks water parameters (amm/nitrite/nitrate)? Fungus & columnaris are both opportunistic illnesses that tend to occur when conditions are less than ideal (may have been situation at your lfs
). I can not guarentee anything here because your fish may be beyond help but its worth a last chance effort!! Good luck!