As with most disputes, your first step should be to try to resolve your complaint directly with the company providing the telephone services, including wireless communications. If you cannot resolve the complaint yourself, then consider filing a complaint with the proper regulatory agency.
If you believe your telephone bill is incorrect, contact your telephone company's customer service office immediately at the telephone number printed on the front of your bill.
If you are not satisfied with the company's response, you may file a complaint with the California Public Utilities Commission. If necessary to keep service on during the investigation, you may deposit the billing amount in dispute with the commission.
California Public Utilities Commission
Consumer Affairs Branch
505 Van Ness Avenue
San Francisco, CA 94102
Phone: (800) 649-7570
If you have complaints about telephone service from one state to another (interstate), international calls and wireless service, contact the Federal Communications Commission.
Federal Communications Commission
Consumer & Governmental Affairs Bureau Consumer Complaints
445 12th Street SW
Washington, D.C. 20554
Phone: (888) 225-5322
If you believe your long-distance service was switched without your knowledge and consent ("slammed"), you should file a complaint with both the California Public Utilities Commission and the Federal Communications Commission.