If anyone is traveling from the US to the UK and needs a visa processed, use an agent.

Getting to the list is a bit of a hassle, but go here: https://www.visainfoservices.com/Pages/Content.aspx?Tag=Independent_visa_services—Los_Angeles_area

The website will push you to the home page. Choose your country, and copy-paste the link into the address bar (from within the website). 

Gar.