Tier 1 Extension Delay- Apply for new/lost US passport?

[lilibella]

I had same day appointment at Croydon PEO on 11/5/2012 to apply for an extension for my Tier 1 General Visa-- did my biometrics, took my payment, etc. At the end of my appointment, the UK Border Agency told me that I was missing an additional letter from my accountant to clarify his first letter and as a result my application got sent to Sheffield. FML...The UK Border Officer told me that they would approve my visa in 2-3 weeks once they receive that letter. The letter from my accountant was received in the Sheffield office on 15/5/2012.

It has now been 5 weeks and still not received my approval for my visa. I have contacted the UK Border Agency multiple times via phone and email and have no response to the status of my visa extension application.. like everyone else on this board.

I need my passport to travel back to the US ASAP but do not want to request the return of my documents since it takes 3 weeks to return (and with the Olympics, I'm assuming it will take 3 months to return my documents). My question is if I should report my US passport as lost so I can get a new passport so i can travel internationally within 4 weeks instead of waiting for some unknown months from the UK Border Agency to return my passport?

I know that the UK Border Agency allows you to show your old passport that has your visa as valid at the border. I've done this before. However, does anyone know if you report your passport as lost, does the UK border agency cancel your visa in process b/c reporting it as lost?