Does anyone have a cure for tendonitis?

I have been suffering with tendonitis in both heels for several months, the pain is so severe, sometimes I cant even walk, Ive been to the doctors and got pain killers (no use) ive been to NHS Physio but they just give me excercises and no treatment, I apply ice packs but that just hides the pain for a short while, does anyone know a cure for the problem, I would be really greatful