Medical negligence Cervical spine surgery disability after operation

I was operated for decompression and fixation at C3 spine. The dr. Gave me in writing zero point five percent risk before operation and its its more than two years now I am on disability after operation. Thete was disc bulge also at c5 c6 in mri prior to operation but dr operated only c3 being cord signal change, myelopathy after seven months o the same dr. Suggested surgery at c5 c6. When I told him that other dr. Claiming that it should be multiple disc bulge surgery. Even they got signed blank consent form and after failure of surgery filled as per their convenient. They gave estimated two lac fifty thousands charged four lac .Please advice legal remedy