BTW the reason why the contacts got messed up is the following. I imported the contacts from my old phone into the Live account and had exported it as a CSV file.  Couple of days later, I imported from the same file. And viola. Some of the cell phone numbers got updated in engineering notations ( numbers like 9845e+11) . Went back to the CSV and checked that indeed some of the phone numbers were stored in engineering notations.  After a painstaking efforts, got the CSV corrected ( from my older cellphone contacts).  And then imported the CSV again.

Live did the import but did not replace the older contacts, just added duplicate entries.   The "Cleanup Contact" feature doesnt work as its output is useless. 

Just need a clean method to delete all my contacts once so that I can start clean