Costco complaints phone number, email address & complaint form.
How to make a complaint to Costco Costco complaints, To make a complaint in Costco you can first make a complaint from the number 011-800-774-2678 given here. If you do not find a solution to your problem by phone, we suggest that you complain by email. About Costco Costco’s worldwide headquarters are in Issaquah, Washington, an eastern suburb of Seattle, although its Kirkland … Read more