Sumanth,
Pay attention to your selection on which forecast was run. MAD or any other measure of forecast error is meaninggful only at the selection level at which forecast is run. Rest is disaggregation and aggregation.
If you try to measure it at some other level in your excel sheets, it will never match. So make a distinction between WHAT you are actually forecasting and WHAT you are reporting the error for.
Hope this general gyan helps
Thanks
BORAT