#3 - Sept. 20, 2010, 6:25 a.m.
He should really be the one to contact Billing.
It does sound like he installed the full game instead of upgrading his linked trial.
That happens from time to time. If it's caught early, Billing can normally sort that out.
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