What to do in case of a security problem

If you suspect a security problem, act on it immediately but without panic.  Delaying may worsen the consequences.  Calling customer service is not the first action you should take.

First, ask yourself which of the following best describes the problem:

1. I can log in.  Someone else is or may be using my account, or my login credentials may no longer be secret.
2. I can log in and I think my login credentials are safe, but unauthorised activity appears to have occurred in my account.
3. I can’t log in.  Someone else is or may be using my account.

The articles below deal with these situations.

I can log in but I'm worried about activity on my account

What do I do if I can't log in?

What happens when I experience losses due to unauthorised usage?