I Have Had Phlegm In My Nose/throat/chest For About Two

I have had phlegm in my nose/throat/chest for about two years now. It's sometimes hard to remove but when I do the phlegm is usually relatively clear. About 6 months ago I saw an ENT doc who scoped my nasal cavities and detected some swelling due to allergies. I was diagnosed with acid reflux and prescribed antacids which I took for a while to no effect. Any other suggestions?