This is years ago, so it may be out of date.
I called and let the phone ring for about 10 minutes, but someone did eventually answer and start the ball rolling.
The FBU London service a number of countries in addition to the UK, some in Africa, and one would imagine staffing levels were not overly generous to start with.
Your first contact with SSA, whether online or on the phone is only for initial contact. From experience of friends, don't contact them before you are ready to start collecting SS. Once contacted, if you're over 62, they will encourage you (somewhat strongly) to start the application. After the initial contact, the real conversation results from a phone call they make to you at a pre-arranged time. It's during this telephone interview your WEP situation will be discussed, although it won't be called that. They'll want to know about all other pensions you are in receipt of, and what pensions you will be in receipt of in the future. They'll also ask about voluntary contributions to those pensions (in your case, the UK State Pension). During my conversation, a recording was made (under perjury, with my agreement) in which you swore all information given was correct. You also provide banking details at this time (or in the follow up paperwork, I forget which).
They then send you an official copy of all information and the application which you sign (under perjury) and return. In a matter of time, the payments begin. After the initial 10 min wait on the phone, the rest went very smoothly, and according the schedule they laid out.
Once contact is made, you should have no problems. BTW, you may also contact the SSA International Office in Baltimore to also start the ball rolling, but my guess is a telephone interview would still be required.
