Address book contacts deleted in one shot

I need to delete all my contacts in my address book site - all in one shot.

I am moving contacts over from another phone. When I imported as a contact card file, there were lot of errors in it. The numbers are in but when I dial, I am getting invalid number error. So now I converted the file to .csv. Cleaned up a lot of bad data. Now I want to upload this on my address book site and sync with phone.

I deleted all the contacts on the phone but immediately, all the bad contacts came back.

I am planning to delete all the contacts in the site first. Then delete all the contacts in the phone, add the new .csv and then let it sync.

But my problem is that I am not finding an option to delete all the contacts together in the site.

Mine is att gophone.