Disallowing the allowances in Form 16

The ITO after scrutinity of my IT returns of the Assessment year 2010-11, issued demand notice by disallowing 50% of the allowances mentioned in the "Form 16" issued by the employer. He demanded the proof for the allowances mentioned in "Form 16", which I had submitted to the employer for claiming the allowances. I informed the Assessing Officer, my inability to show the proof as I do not have the proof with me. As I left the employer before 4 years, I cannot approach the employer for the original bills. I made appeal to the Appealate Authority, who dismissed my appeal mentioning "mere allowance by the employer in Form 16 cannot also be treated as a substitute for verification by the AO at the time of scrutinity proceedings since the relevant provisions under the Act stipulate that the exemption can be claimed only upon AO being satisfied that such expenses claimed under various heads were actually incurred by the appealant for that purpose.The information proviced by the employer in Form 16 can, therefore, at best be treated as information and not as the final outcome of the allowability of the claim." Kindly suggest me how to proceed further.