#6 - June 22, 2010, 7:30 a.m.
Resetting, and removing/installing a new serial number (which in effect is a new authenticator) are two things a bit different.
Billing can assist with this. I recommend anyone with a mobile app jot down their serial number and keep it in a safe spot for just this contingency. This is MUCH easier to accomplish on the phone if you have the old serial number.
Billing and Account Services
Phone Support - 1 (800) 59-BLIZZ (1 (800) 592 5499)
Live Representatives Available 7 days a week, 7am to 8pm Pacific Time
E-mail Support - Billing@Blizzard.com
Players in Australia should call 1-800-041-378
Players in Singapore should call 800-2549-9273
Players in Chile should call 1230-020-5554
Players in Mexico should call 001-888-578-7628
Players in Argentina should call 0800-333-0778
All other international players should call: (949) 955-0283