Billing Companies
When you joined the membership site, your credit card was charged by a billing company (= "payment processor").
If you have lost your password or need to cancel your memberhip you must contact that billing company.

You should have received a confirmation email from that billing company after you joined the membership site. This email will contain the information you need to retrieve your password or cancel your membership. Below is a list of the most common billing companies. Please find the one that charged your credit card and contact them directly.